Sonja Lemke

Sonja Janet Lemke (born 22 November 1991) is a German politician of Die Linke and a member of the Bundestag from North Rhine-Westphalia. The Bundestag biography, which the parliament bases on members' own statements, gives Berlin as her birthplace and lists her occupation as computer scientist (Informatikerin). She took her seat when the 21st Bundestag was constituted on 25 March 2025, elected from place 5 of the North Rhine-Westphalia state list after standing in constituency 142, Dortmund II.

She studied at the Technical University of Dortmund. From June 2016 to June 2017 she wrote a master's thesis in Jürgen Altmann's experimental-physics group, "Two- and Three-dimensional Localisation of Acoustic and Seismic Signals by the Hyperbolic Method," in the field her Bundestag biography describes as physics with a focus on "physics and disarmament." On 31 March 2017 she presented "Ortung seismischer Signale" to the German Physical Society's working group on physics and disarmament, on locating seismic sources for verification of the Comprehensive Nuclear-Test-Ban Treaty, monitoring of nuclear-waste repositories, and oversight of ceasefire agreements. She also holds a bachelor's degree in computer science and has worked as a software developer and as a substitute teacher.

Lemke joined Die Linke in 2016. From 2020 she sat on the council of Dortmund and on the district representation for Innenstadt-Nord, and on the digital committee of the Landschaftsverband Westfalen-Lippe; the Bundestag's disclosure of members' interests records the council seat as ending on 31 October 2025. In December 2023 the Dortmund district association elected her district spokesperson (Kreissprecherin), with Kevin Götz as co-spokesperson. At the 2021 federal election, as Sonja Janet Lemke, she received 5,823 first votes (4.1 percent) in Dortmund II, then constituency 143. On 23 February 2025 she received 13,794 first votes (9.0 percent) in the renumbered constituency 142; Sabine Poschmann of the Social Democratic Party of Germany won the direct mandate with 49,553 votes (32.4 percent).

In the 21st Bundestag she is a full member of the Committee on Digital Affairs and State Modernisation and of the Committee on Research, Technology, Space and Technology Assessment, where she is her group's Obfrau, a deputy member of the Committee on Culture and Media, and a parliamentary secretary (Schriftführerin). Her parliamentary office is in Berlin, with constituency offices at Stefanstraße 2 in Dortmund and Werler Straße 61 in Hamm.

Published ancillary interests include a seat on the supervisory board of Flughafen Dortmund GmbH until 30 November 2025, remunerated at 2,200 euros a year plus irregular payments, membership of the Landschaftsversammlung of the Landschaftsverband Westfalen-Lippe until 22 January 2026, and, from 9 December 2025, the advisory board of Stiftung Datenschutz in Leipzig. The same disclosure records support from the Wilhelm and Else Heraeus Foundation for two stipend placements in 2026, each of 13,500 euros.

Early life and education

Official records agree that Sonja Janet Lemke was born in 1991, but they give different places of birth. The Bundestag biography, which the parliament states is based on members' own information, gives 22 November 1991 in Berlin and describes her as unmarried. The Federal Returning Officer's February 2025 candidate directory for the election to the 21st Bundestag, drawn from the minutes admitting nominations, enters "1991, Dortmund" as year and place of birth and gives her residence as 44147 Dortmund. The North Rhine-Westphalia returning officer's file of 2025 state-list candidates records the same full name, the occupation Informatikerin (computer scientist) and Dortmund as her residence. None of these notes records a school or any other detail of her childhood.

Physics studies and disarmament research

The Bundestag biography states that Lemke studied in Dortmund and completed a master's degree in physics in the field of "Physik und Abrüstung" (physics and disarmament). The Physics and Disarmament group in Experimental Physics III at the Technical University of Dortmund lists her master's thesis for June 2016 to June 2017: "Two- and Three-dimensional Localisation of Acoustic and Seismic Signals by the Hyperbolic Method."

The group continues the Bochum Verification Project, founded in 1988 at the Institute for Experimental Physics III of Ruhr University Bochum to study automatic sensor systems for verifying disarmament and peace-keeping arrangements. Students in the group use geophones, microphones and analogue-to-digital converters, and write their own signal-processing routines. The published list does not itemise the measurements or programs used in Lemke's thesis beyond the title and dates.

During the thesis she gave the talk "Ortung seismischer Signale" ("Localisation of seismic signals") at the German Physical Society meeting in Münster. It was contribution AGA 7.3 in the session "Seismic and Acoustic Verification" of the society's Physics and Disarmament working group, on Friday 31 March 2017, from 11:30 to 12:00, in lecture hall S Aula; the session ran from 10:30 to 12:00. The session overview says the working group, founded in 1998, held the meeting with the Research Association for Science, Disarmament and International Security (FONAS), on disarmament, non-proliferation, new military technologies and verification of arms-control agreements.

The abstract names only Lemke, affiliated with Experimental Physics III at TU Dortmund, and gives three uses of locating seismic sources: verification of the Comprehensive Nuclear-Test-Ban Treaty, monitoring of nuclear repositories, and monitoring of ceasefire agreements. It argues that seismic methods can limit intrusion. Geophones at a repository can sit outside the sealed site and near the surface, and, in checks on ceasefire and disarmament agreements, the recorded information can be kept to the minimum required so that the parties' military secrets are protected. Time differences between geophones were estimated by cross-correlation and by the ratio of the short-term average to the long-term average of the signal amplitude. A direct geometric reconstruction, the hyperbolic method named in the thesis title, is described as needing four sensor locations; a maximum-likelihood method can use more sensors and is said to tolerate errors better. The algorithms were checked on real and theoretical signals. The abstract also treats difficulties specific to seismic waves, including unknown speeds and reflections.

Computer-science degree

The Bundestag biography also records a bachelor's degree in computer science ("Bachelorabschluss Informatik"), without naming the institution, the year, or whether it preceded or followed the physics master's. In that sentence the degree follows work as a software developer and as a substitute teacher. Separately, the Bundestag, the federal candidate directory and the North Rhine-Westphalia state-list file all give her occupation as Informatikerin.

Professional career

Public information on Sonja Lemke's work before she became a member of the Bundestag on 25 March 2025 is limited. Her parliamentary biography, which the Bundestag notes is based on members' own statements, lists her as an Informatikerin (computer scientist). It says that she studied in Dortmund, holds a master's degree in physics focused on "physics and disarmament" (Physik und Abrüstung), worked as a software developer and a substitute teacher, and holds a bachelor's degree in computer science. The entry names no employer, school, dates of employment, or subject taught.

Software development

A Facebook post by Die Linke in Dortmund described Lemke, then 28 and living in the Nordstadt, as having studied physics at the Technical University of Dortmund and as working as a software developer (Softwareentwicklerin). The post names no company, product, or period of employment. Because she was born on 22 November 1991, the stated age of 28 places the text before 22 November 2020.

Nominations filed the next year used a different occupational title. For the 2021 federal election, the Federal Returning Officer recorded her occupation or status (Beruf oder Stand) in constituency 143, Dortmund II, as physicist (Physikerin). The Dortmund constituency committee admitted that nomination on 29 July 2021, and the local report of the decision likewise gives her occupation as physicist and her residence as Dortmund. On 21 June 2021 Radio 91.2 described the 29-year-old candidate as a physicist who already sat on the city council. None of these accounts mentions software development.

For the 2025 election the occupation on file was computer scientist. The Federal Returning Officer's final-results volume lists Sonja Janet Lemke, born in 1991, as an Informatikerin for Die Linke, on place 5 of the North Rhine-Westphalia state list and in constituency 142, Dortmund II; the state's candidate file gives the same occupation and residence. Where more than one occupation was supplied, the returning officer's booklet used, so far as it could be determined, the one principally exercised, and for dual candidacies the constituency nomination. Radio 91.2 on 21 January 2025 also called the 33-year-old an Informatikerin. None of these sources names a software employer, and the Bundestag text does not say when the computer-science degree was completed.

Substitute teaching

Substitute teaching is attested only in that self-statement. The biography places Vertretungslehrerin in the same sentence as the software-development work and the computer-science degree, without a school, subject, hours, or dates.

The 2020 party post, the 2021 nomination as a physicist, and the 2025 nomination and Radio 91.2 profile as a computer scientist do not mention teaching. The outside activities published with the biography are public offices rather than school employment, and they cover reportable activity after she took her seat. They do not name a school or independently corroborate substitute teaching.

Local politics in Dortmund

City council and Innenstadt-Nord

At the municipal election of 13 September 2020 in Dortmund, in North Rhine-Westphalia, Die Linke received 11,825 votes (5.6 percent) and five of 90 council seats, all from the reserve list; turnout was 47.1 percent. Sonja Janet Lemke was elected from fifth place on that list. The constitutive meeting on 12 November 2020, with all 90 councillors present, placed her in the group Fraktion DIE LINKE+. That group's committee slates also named Christian Gebel of the Pirate Party Germany and Michael Badura of the Tierschutzpartei, each elected from a one-seat list.

The council of the City of Dortmund in session in May 2025.

The November 2020 minutes made her a voting member of the committees for finance, holdings and property; for climate protection, the environment, urban design and housing; and for mobility, infrastructure and green space, and a substitute on the committee for personnel, organisation and digitalisation. SessionNet later listed voting membership of the housing and mobility committees until 12 November 2025, a voting finance seat until 13 February 2025 and then a substitute seat from 27 March to 12 November 2025, and the personnel-and-digitalisation substitute seat until 13 February 2025. In 2025 she told Nordstadtblogger that, at her first finance-committee meeting, a male representative had asked whether she had understood anything at all.

In Innenstadt-Nord, Die Linke took 1,099 votes (14.6 percent) and three of 19 seats on the Bezirksvertretung; turnout was 24.5 percent. Lemke was third on the list, after Cornelia Wimmer and Michael Gründel, and was recorded among those elected. The representation constituted on 11 November 2020 in the Dietrich-Keuning-Haus, and the one councillor of Die PARTEI joined the Linke group. SessionNet lists Lemke as a voting district member until 18 March 2025. Her Bundestag disclosure records the council seat as ending on 31 October 2025, with a monthly gross allowance of 541 euros and irregular gross payments of 289.96 euros in 2025; SessionNet still showed a voting council mandate until 12 November 2025. The same 2020 minutes named her one of the city's representatives on the supervisory board of Flughafen Dortmund GmbH, which operates Dortmund Airport; the disclosure describes that seat as held ex officio and as ending on 30 November 2025.

Landschaftsverband Westfalen-Lippe

Members of the Landschaftsversammlung of the Landschaftsverband Westfalen-Lippe are chosen by the councils of the association's counties and independent cities, one member for every 100,000 inhabitants. On the continuation of Dortmund's constitutive meeting, on 26 November 2020, the council elected Lemke a full member of the 15th assembly and Petra Tautorat her substitute. The association, based in Münster, covers about 8.3 million people in Westphalia-Lippe and runs regional social, psychiatric, school and cultural services. Her Bundestag biography, drawn from members' own statements, also lists a seat on the association's digital committee. An anti-corruption declaration for the 15th assembly period gives her profession as an M.Sc. in physics and records the airport-board membership. The Bundestag disclosure lists the assembly seat as ending on 22 January 2026 and states no remuneration for it, unlike the council allowance. The LWL's 2026 brochure for Dortmund, for the 16th period (2025–2030), names other city delegates and does not include Lemke.

Municipal campaigns

In February 2023, after a protest camp of homeless people on the Kampstraße had been removed, Lemke told RUHR24 that it helped nobody if homeless people were pushed into other streets or even fined. DIE LINKE+ called for more Housing First flats, saying that some already existed, arranged by the city or by social initiatives, but not enough, and that politics and the administration had a responsibility to expand permanent housing with support. The city told the same outlet that the state Housing First programme was aimed at welfare associations and private landlords and that the municipality saw itself mainly as an intermediary.

When Die Linke presented its programme for the 2025–2030 municipal term in July 2025, under the title "Gemeinsam. Solidarisch. Gerecht: Unser Dortmund", Lemke said that lifting the share of publicly subsidised housing from 25 to 30 percent was only a first step and that the party was seeking as much as 70 percent nationwide. She presented the transport section: local public transport free of charge for pupils, apprentices and people on transfer benefits; 30 km/h as the usual speed limit inside built-up areas; and resident-parking fees tied to income, lower in economically disadvantaged areas. At the district election of 14 September 2025, Nordstadtblogger reported that Die Linke placed first in Innenstadt-Nord with 23.58 percent, ahead of the SPD, with four seats on a list led by Milena Mehlmann.

Activity in Die Linke

Entry and local organisation

Sonja Lemke joined Die Linke in 2016, according to the biography published by the Bundestag. That biography places her subsequent activity in Dortmund, in North Rhine-Westphalia: from 2020 she was a member of the city council and of the Bezirksvertretung Innenstadt-Nord, and sat on the digital committee of the Landschaftsverband Westfalen-Lippe. Inside the party, her organisational base was the Dortmund Kreisverband. The district association later grew sharply while she was its spokesperson. On 10 February 2025 Nordstadtblogger reported that the Dortmund Linke had reached what it called a high of more than 400 members and stood at 521 at the beginning of February, after 40 joiners in November 2024, 26 in December and 122 in January. A statement from the association, carried on the same page, said membership had more than doubled in three months, to 700, including 210 joiners in February up to the date of the statement.

District spokesperson

In December 2023 the Dortmund membership elected a new district executive. Lemke, then 32, became Kreissprecherin (district spokesperson), with Kevin Götz, 29, as Kreissprecher. Jan Siebert was elected treasurer and Jörg Kleine managing director (Geschäftsführer); Max Siekmann and Payton Gall joined as assessors (Beisitzer). Nordstadtblogger reported that all six were being chosen by the members for those offices for the first time, although they brought experience from youth or party structures and from social movements.

Götz called the vote a signal from the membership to look ahead, and said the board wanted to stand with people who felt cut off by social inequality and with those affected by poverty and rising prices. Lemke described Die Linke as the party of social justice and said it stood for climate justice, peace and a society without discrimination, arguing that a broader shift to the right made that stance necessary. She was still referred to as Kreissprecherin in the February 2025 membership report.

North Rhine-Westphalia list

The state party set its list for the 2025 German federal election at a Landesvertreterversammlung on 11 January 2025 in the Stadthalle in Kamen. Scharf Links reported that about 220 delegates sent 20 candidates into the campaign. Sascha H. Wagner of Dinslaken, state spokesperson of Die Linke in North Rhine-Westphalia since 2022 and state business manager from 2012 to 2020, took first place with 81.5 percent. Cansin Köktürk of Bochum was second with 66.7 percent, and Lea Reisner third with 90.1 percent.

The Landeswahlleiterin's final file of successful state-list candidates records Sonja Janet Lemke, an Informatikerin living in Dortmund, in fifth place. Fourth was Ulrich Thoden, a teacher from Münster; sixth was Mirze Edis, a steel-construction locksmith from Duisburg. The same file gives the first three places to Wagner, an employee from Dinslaken; Köktürk, a social worker from Bochum; and Lea Valeska Anissia Reisner, a nurse whose residence was given as Berlin. On the return for Dortmund II (Wahlkreis 142), Lemke is likewise listed for Die Linke with North Rhine-Westphalia list place 5. Ruhr Nachrichten named her and Jan Siebert as Dortmund's Bundestag candidates and wrote that their chances were decided that Saturday a short distance from the city; the headline treated a seat for Lemke as a realistic prospect.

Die Linke polled 877,123 second votes in the state, 8.3 percent, up 4.6 points on 2021. The final statewide result gave the party 13 of the 136 seats filled from North Rhine-Westphalia, compared with 47 for the CDU, 31 for the SPD, 26 for the AfD and 19 for the Greens. None of the 64 constituency seats went to Die Linke. On 11 March 2025 the Landeswahlausschuss provisionally declared elected the state-list candidates in places 1 to 13, Lemke among them, and noted that membership of the Bundestag still depended on the Bundeswahlausschuss, which met in Berlin on 14 March. The mandate took effect when the new Bundestag opened on 25 March 2025. The Landeswahlleiterin's final candidate file contains the same thirteen Die Linke names, numbered consecutively from 1 to 13.

Bundestag candidacies and elections

2021 candidacy in Dortmund II

At the 2021 German federal election on 26 September 2021, Sonja Janet Lemke was the constituency candidate of Die Linke in Wahlkreis 143, Dortmund II, a seat inside the city of Dortmund in North Rhine-Westphalia.

The constituency had 199,317 eligible voters. Turnout was 72.2 percent, with 143,855 people voting. Of 142,557 valid first votes, Lemke received 5,823, or 4.1 percent; 1,298 first votes (0.9 percent) were invalid.

The direct mandate went to Sabine Poschmann of the Social Democratic Party of Germany, with 55,695 votes (39.1 percent). Michael Depenbrock of the Christian Democratic Union of Germany was second with 28,897 (20.3 percent), followed by Anke Weber of Alliance 90/The Greens with 21,028 (14.8 percent), Matthias Helferich of the Alternative for Germany with 11,816 (8.3 percent) and Frieder Cornelius Löhrer of the Free Democratic Party with 10,270 (7.2 percent).

On the party vote in the same constituency, Die Linke received 6,361 second votes, 4.5 percent of 142,790 valid second votes. The SPD led that ballot with 51,080 votes (35.8 percent). The first-vote result did not elect Lemke from Dortmund II.

2025 election and list mandate

Lemke stood again at the 2025 German federal election on 23 February 2025, in the renumbered Wahlkreis 142, Dortmund II. The North Rhine-Westphalia returning officer listed her for Die Linke both as the constituency candidate and in fifth place on the state list (Landesliste Nordrhein-Westfalen).

There were 195,508 eligible voters, 3,809 fewer than in 2021. Turnout rose by 6.8 percentage points, to 78.9 percent (154,308 voters). Valid first votes numbered 152,770, with 1,538 invalid (1.0 percent).

Lemke received 13,794 first votes (9.0 percent), 7,971 more than in 2021 and a gain of 4.9 percentage points. Poschmann again won the constituency, with 49,553 votes (32.4 percent). Depenbrock followed with 37,891 (24.8 percent). Helferich, again the AfD candidate, took 28,240 (18.5 percent), ahead of Hannah Sophia Rosenbaum of the Greens with 15,742 (10.3 percent). Nils Mehrer of the FDP received 4,047 (2.6 percent) and Nadja Reigl of Die PARTEI 3,503 (2.3 percent).

Of 153,330 valid second votes (978 invalid, 0.6 percent), Die Linke received 15,616, or 10.2 percent, 5.7 points above 2021. The SPD led with 37,511 (24.5 percent), then the CDU with 36,025 (23.5 percent), the AfD with 27,597 (18.0 percent) and the Greens with 17,291 (11.3 percent). Bündnis Sahra Wagenknecht, which had no constituency candidate, took 7,330 second votes (4.8 percent), and the FDP 5,406 (3.5 percent).

Statewide, Die Linke polled 877,123 second votes in North Rhine-Westphalia, 8.3 percent of 10,526,134 valid second votes, up from 3.7 percent in 2021. The final state result assigns the party 13 seats. Dortmund II’s 10.2 percent second-vote share was above that state figure.

The Federal Returning Officer’s register of members elected on state lists in North Rhine-Westphalia names Sonja Janet Lemke as Die Linke’s fifth successful candidate, at list place 5; the 13 people on that party list account for the party’s seats from the state, and Poschmann is recorded separately as the constituency winner. The Bundestag biography states that Lemke was elected via the North Rhine-Westphalia state list, with a candidacy in Wahlkreis 142. The 21st Bundestag held its constituent sitting on 25 March 2025.

Constituency profile

Wahlkreis 142 lies entirely within the district-free city of Dortmund. The Federal Returning Officer assigns to it the district Innenstadt-Nord, in Stadtbezirk Innenstadt, together with the boroughs Eving, Scharnhorst, Brackel, Aplerbeck and Hörde. The city’s other boroughs and districts form Wahlkreis 141, Dortmund I.

In 2021 the same districts made up Dortmund II, then numbered 143, and the rest of the city was the then Wahlkreis 142, Dortmund I. The 2025 redistribution changed the number from 143 to 142; the official description of the included districts did not change.

Hamm is not part of the constituency. Under the 2025 division it is in Wahlkreis 144, Hamm – Unna II. Lemke’s Bundestag profile lists a constituency office in Hamm (Werler Straße 61) as well as one at Stefanstraße 2 in Dortmund; the Hamm address is an office, not territory of Dortmund II.

Turnout in the constituency stayed below the state rate. In 2025 it was 78.9 percent in Dortmund II and 82.2 percent in North Rhine-Westphalia; in 2021 the figures were 72.2 and 76.4 percent.

Mandate and parliamentary offices

Entry into the 21st Bundestag

Lemke took her seat when the 21st Bundestag was constituted on 25 March 2025, after the 2025 German federal election. She sits for the parliamentary group of Die Linke. The Federal Returning Officer’s list of those elected records Sonja Janet Lemke, born in 1991, for Die Linke at place 5 on the state list of North Rhine-Westphalia, with constituency 142, Dortmund II, as her candidacy. The Bundestag biography gives the mandate in the same terms: elected on the state list (Gewählt über Landesliste), and a constituency candidate in Wahlkreis 142 rather than the winner of that direct seat.

Sonja Lemke of Die Linke speaking in the plenary chamber of the Bundestag in Berlin on 16 April 2026.

The list seat did not itself assign the later offices. The two committees on which she is a full member were constituted on 21 May 2025. The plenary elected her a parliamentary secretary only on 9 July 2026, in succession to another member of her group. The biography’s list of those posts is dated 30 October 2026.

Committees and rapporteur roles

As of that biography, Lemke is an ordinary member of the Committee on Digital Affairs and State Modernisation (Ausschuss für Digitales und Staatsmodernisierung) and of the Committee on Research, Technology, Space and Technology Assessment (Ausschuss für Forschung, Technologie, Raumfahrt und Technikfolgenabschätzung). She is Obfrau of the research committee only, and a deputy member of the Committee on Culture and Media (Ausschuss für Kultur und Medien). The biography does not list a seat on any information-technology commission of the Council of Elders.

Each of those full committees has 30 ordinary members. At the research committee’s constitutive sitting, Die Linke’s ordinary members were Anne-Mieke Bremer, Nicole Gohlke and Lemke. On the digital-affairs committee they were Bremer, Lemke and Donata Vogtschmidt. The sitting described that committee’s work as network policy—digital sovereignty, digital infrastructure, the digital economy and the digital state—together with state modernisation.

An Obfrau or Obmann is not the committee chair. Each parliamentary group names one per committee as its leadership’s main contact. The Obleute help set the group’s line in deliberations, agree agendas and plan the business, and follow the detail of the committee’s work. On the Bundestag biography that designation is attached to Lemke only for the research, technology, space and technology-assessment committee.

Rapporteurs are named item by item, so more than one member of a group can hold them on the same committee. The agenda for the research committee’s 29th sitting, on 23 September 2026, lists Lemke as Die Linke’s rapporteur for the draft First Act amending the Wissenschaftsfreiheitsgesetz (printed paper 21/4500), for the government report on a research-data law, and for Einzelplan 30, the research chapter of the 2027 federal budget. Nicole Gohlke, not Lemke, is the group’s rapporteur for other items on that agenda.

The group’s own spokesperson list, which is not a Bundestag office, names Lemke as its policy spokesperson for digital administration and open government and for research and technology. That faction brief does not appear on the Bundestag biography as an Obfrau role for the digital-affairs committee.

Parliamentary secretary and constituency offices

On 9 July 2026, opening the 89th sitting, President Julia Klöckner took a proposal from Die Linke that Lemke be elected a parliamentary secretary (Schriftführerin) in succession to Mareike Hermeier. Klöckner asked whether there was any objection, said she saw none, and declared Lemke elected. She called the task an honorary office (Ehrenamt). The biography lists “Schriftführer/in” among Lemke’s Bundestag functions.

The Bundestag elects these secretaries on proposals from the groups. In the 21st electoral term there are 64, who rotate on sitting days. Two at a time sit beside the presiding officer and, with that officer, form the sitting’s board (Sitzungsvorstand); as a rule one comes from the government side and one from the opposition. They receive requests to speak and motions, keep the speakers’ list and establish the result of votes. At recorded votes they also take in and count the ballot papers.

The biography gives her Berlin office as the Bundestag address, Platz der Republik 1, 11011 Berlin. It also lists two offices headed Wahlkreisbüro: Stefanstraße 2, 44135 Dortmund, and Werler Straße 61, 59065 Hamm.

Parliamentary work

Digital affairs and state modernisation

In the 21st Bundestag, Sonja Lemke (Die Linke) argued that digital bills of the CDU/CSU–Social Democratic Party of Germany coalition favoured firms over users. On 17 October 2025, on an Alternative for Germany motion against EU “chat control” (Drucksache 21/2240), she said scanning every message, including those to family, lawyers and journalists, would end confidential communication. She called the rejection of only “suspicionless” scanning deliberately narrow, said the Interior Ministry still treated client-side scanning of known illegal material as compatible with encryption, and argued that sexual violence against children was being used to justify mass surveillance. Asked by the president to moderate her language, she said the decision had merely been postponed.

In the 2026 budget debate on 25 November 2025 (Einzelplan 24) she said a summit and charter on “digital sovereignty” had centred business, treated open source as an exception, and sidelined civil society and the Centre for Digital Sovereignty (ZenDiS). At first reading on 16 January 2026 of the laws implementing the EU Data Act and Data Governance Act, she said users of Internet of things devices still could not stop manufacturers collecting data, and that Germany had no enforceable open-data right and no transparency law to develop the Freedom of Information Act. At the final reading on 26 March 2026 she said the Federal Network Agency lacked staff for the AI regulation, the Digital Services Act and the Data Act, and accused Digital Minister Karsten Wildberger of seeking, via a “digital omnibus”, to lift the Data Act and preferably the General Data Protection Regulation for “small mid-caps” of 250 to 750 staff.

On 25 June 2026, on an AfD motion for a national rather than EU wallet (Drucksache 21/6650), she said European standards were not being met, that only a skeleton service would exist by 2 January 2027, and that use would depend on Google or Apple accounts. At the final vote on the Digitale Identitätengesetz on 15 October 2026 she said municipalities were unprepared, that firms could request signed identity data without a necessity test—a “cookie-banner 2.0”, as she put it—and that distribution only through US app stores contradicted official sovereignty claims. She opposed a minimum age of 13. A Left motion requiring a legal basis for each query, and a motion from Alliance 90/The Greens, failed; the law passed. That day she also opposed the government’s regulatory-sandbox bill, which she said lacked any duty of scientific evaluation.

Research, technology and technology assessment

Lemke treated the Hightech Agenda as a diversion from the condition of science. On 13 November 2025, after Research Minister Dorothee Bär, she said planned artificial intelligence data centres mainly consumed electricity, that efficiency rules were to be weakened, and that studies she cited found no productivity gain for firms. On 28 November 2025, on Einzelplan 30 of the 2026 budget, she said billions, including agenda funds, were frozen for want of a plan, and that the National Research Data Infrastructure was being shifted into a special fund without new money. On 11 September 2026, in the first reading of the 2027 research budget, she said a €760 million global underspend left funds unusable, that little of the money voted for research on post-infectious diseases had been spent, and that planned “AI gigafactories” were an unexplained data centre of about one gigawatt.

On 20 March 2026, debating the bill implementing the EU AI regulation (Drucksache 21/4594) and her group’s motion on the societal risks of AI (Drucksache 21/4758), she said ministers wanted to delay high-risk rules, that retrospective remote biometric identification stayed legal, and that Palantir Technologies-style analysis was not stopped. She demanded disclosure of training data, warning of biased social-administration decisions and of creative works used without pay. In a Green topical hour on 25 September 2026 she said regulation was necessary, but that the debate was being set by executives whose models were no longer improving and not yet profitable. She led written questions on AI in the federal administration (20 October 2025, Drucksache 21/2310; reply of 21 November 2025, Drucksache 21/2892) and on the agenda’s six “key technologies” (23 December 2025, Drucksache 21/3433).

On academic freedom, on 25 June 2026 she answered an AfD motion on research fraud by accusing that party of rejecting climate and vaccination research and of wanting to abolish gender studies and postcolonial studies, and she called for a ban procedure. On 24 September 2026 she opposed the first amendment of the Wissenschaftsfreiheitsgesetz: she said it ignored short contracts and abuse of power and instead let more publicly funded institutes exceed public-sector pay ceilings for senior staff, while coalition amendments, on her account, dropped the research ministry’s duties of information and control. On 15 October 2026, on an AfD motion against scientific espionage (Drucksache 21/8554), she said publication is how results are tested, criticised the handling of allegations at CISPA, and opposed origin-based checks and suspicion of researchers from China. A question of 17 February 2026 (Drucksache 21/4161) asked how the Max Planck, Fraunhofer, Helmholtz and Leibniz associations handled complaints of abuse of power.

Culture, media and other plenary interventions

On 19 December 2025, in an AfD topical hour demanding abolition of the Digital Services Act in the name of online speech, Lemke said advertising-funded platforms amplified far-right material. She defended the Act’s notice-and-action rules, ban on dark patterns and limits on advertising by religion or politics, called a €120 million fine against X too small, and asked for a ban on personalised advertising and for non-commercial alternatives such as Mastodon. She called the motion a favour to US associates of the AfD and said the party should be banned.

On 9 October 2026 she intervened in debate on an AfD motion for a “Migrationswende” (Drucksache 21/8387). She told Detlef Seif (CDU/CSU) that the preceding speech was racist for reducing people to skin colour, called the right of asylum a consequence of the Second World War, and defended family reunification for children. Seif answered that the AfD speech was inhumane, but that the day’s subject was migration policy, which the coalition was carrying out.

Political positions

Digital policy and data protection

In the Bundestag on 16 May 2025, Sonja Lemke of Die Linke called the CDU/CSU–SPD "digital-only" course a "policy of leaving people behind," excluding older people, people who could not afford devices, and people with disabilities. "Digital sovereignty," she said, meant sovereignty for private business, while data protection was "protection of fundamental rights," not a means of monetizing data; a mandatory electronic patient record would pool intimate health data without consent as politicians discussed giving such data to the police, and she said parliamentary state secretary Philipp Amthor had wanted the Freedom of Information Act abolished in the coalition talks.

On 25 November 2025, in the budget debate for the Federal Ministry for Digital Transformation and Government Modernisation, she said a sovereignty summit had "rolled out the red carpet for corporations" and treated open-source software as a cybersecurity exception, so that European billionaires would replace American ones rather than infrastructure passing into public hands. An 8 percent staff cut and flat funding for the Federal Network Agency would, she said, weaken enforcement of the Digital Services Act, the Data Act and rules on artificial intelligence, while the European Union "digital omnibus" would delay the AI regulation, free personal data for training and exempt pseudonymized movement profiles from data-protection law. Minister Karsten Wildberger countered that there was "no competitiveness without AI" and that rules should protect fundamental rights without blocking innovation.

On 19 December 2025 she answered an Alternative for Germany motion to abolish the DSA, which AfD speakers cast as a defense of online free expression. Lemke called it a concession to Elon Musk, defended duties to act on illegal content and limits on dark patterns and sensitive-category advertising, and said a €120 million fine against X was too small; AfD deputies compared the reporting rules to the Stasi. She argued for banning personalized advertising and for non-commercial networks instead of profit-driven platforms.

Science, technology and disarmament

In her first Bundestag speech, on 15 May 2025, Lemke said the coalition agreement offered "sham solutions"—a fusion plant decades from supplying power, a Hyperloop she tied to burying high-speed rail, and an energy-hungry AI "gigafactory"—instead of research for the climate crisis. The scandal, she said, was expanding military research while ending "every existing separation between military and civilian research"; she wanted publicly funded research aimed at the common good rather than private interests. CDU deputy Stephan Albani answered with a transfer agenda for applied research, less bureaucracy and more flexibility for institutes.

In an nd interview of 30 November 2025 she called the Hightech Agenda "a large distraction maneuver": AI, quantum computing and fusion stood in for renewables, trains and action on social division, and she wanted public data centers and open-source alternatives rather than subsidies for private chip plants. Generative systems, she said, reproduced racism and sexism and relied on unpaid creative work and low-paid labeling, including in Kenya; subsidies should require good jobs, ecological criteria and democratic control. In February 2025 she wrote that even defensive rearmament fed an arms spiral and that satellite-verifiable disarmament treaties were safer; her questioner said the threat to Germany and Europe made stronger defense unavoidable.

Housing, social policy and migration

Before the 2025 election Lemke told Radio 91.2 that, for Dortmund, she wanted a rent cap, including on commercial premises, and socialization of large profit-oriented housing companies, because housing was a basic right, together with more rail and buses, the Deutschlandticket on the way to fare-free local transport, and debt relief for Ruhr municipalities. Her January 2025 application for Die Linke's North Rhine-Westphalia list named Vonovia and Peach Property as drivers of rent rises and said she had organized demonstrations with Gemeinsam gegen Vonovia and had long sought a rent cap, open-ended social-housing ties and public ownership. The 2025 coalition agreement, as read by the real-estate association IVD, instead extended the Mietpreisbremse—new leases in tight markets at most 10 percent above the local reference rent—by four years to the end of 2029, with neither a hard ceiling nor socialization.

In the November 2025 budget debate she said the coalition was cutting the welfare state, campaigning against the poorest, and refusing wealth and inheritance taxes. On migration, her September 2021 reply on Abgeordnetenwatch said family reunification should be unrestricted, including for subsidiary protection, and that unaccompanied minors should be able to bring siblings, because "every person has the right to be safe with their family."

Outside offices and disclosures

Corporate and public-body seats

The code of conduct for members of the Bundestag is set out in §§ 44a to 52a of the Members of the Bundestag Act. The mandate is to stand at the centre of a member’s activity; other work is in principle allowed, but members must notify the President of the Bundestag of their last occupation, paid work beside the mandate, functions in companies, public-law bodies, associations and foundations, shareholdings, agreements on future activities or advantages, and donations or other benefits in money’s worth. Outside earnings above €1,000 in a month or €3,000 in a year are declared to the cent and published with the other notifiable items under § 47. The disclosure rules have formed part of the Act since 19 October 2021. Notices under §§ 45 ff. are due within three months of taking the seat and of any later change, and are published only after a check that publication is required. The biographical text is the member’s own account (Selbstauskunft), separate from those declarations.

On the page dated 30 October 2026, Sonja Lemke’s published company function was an ex officio seat (von Amts wegen) on the supervisory board of Flughafen Dortmund GmbH in Dortmund until 30 November 2025, at €2,200 gross a year, plus irregular payments in 2025 of €220 gross. Under public-law bodies the same record lists membership of the Landschaftsversammlung of the Landschaftsverband Westfalen-Lippe in Münster until 22 January 2026, with no payment figure, and membership of the Dortmund city council until 31 October 2025, at €541 gross a month, plus irregular payments in 2025 of €289.96 gross. That assembly’s members are elected by the councils of the association’s 18 districts and nine independent cities, one seat per 100,000 inhabitants, in line with municipal-election results.

Advisory roles and third-party support

On 13 November 2025 the Bundestag elected the parliamentary members of the advisory board of the Stiftung Datenschutz in Leipzig, adopting proposals from the CDU/CSU, Alternative for Germany and the SPD (Drucksache 21/2727), Alliance 90/The Greens (21/2728) and Die Linke (21/2729), with Lemke the Linke nominee. Founded in 2013 by the Federal Republic, the foundation describes itself as an independent charity promoting data protection among politics, supervisory authorities, business, research and society. The Bundestag calls the board honorary: it advises the executive board and administrative council, may propose projects, and also includes representatives of institutions and associations. Lemke’s declaration records membership from 9 December 2025 and gives no income figure. A foundation list dated May 2026 names her as appointed by the Bundestag.

Under donations and other benefits for political activity, the declaration records two placements by the Wilhelm und Else Heraeus-Stiftung in Hanau: a woman scholarship holder from 1 March to 31 May 2026, at €13,500, and a man scholarship holder from 1 September to 30 November 2026, also at €13,500. The foundation was set up in 1963 by Wilhelm Heinrich Heraeus, a grandson of the founder of the Hanau firm now Heraeus, and by Else Heraeus, to support research and training in the natural sciences, especially physics, and it works with the German Physical Society. Its programme “Wissenschaft trifft Politik” places physicists who have recently completed a doctorate, or at least submitted the dissertation, in a member’s office for usually three months, at an allowance the foundation states as €4,500 a month; each sum published for Lemke equals three months at that rate.

Public presence

Media interviews

Before the 2025 election to the Bundestag, published questioning of Sonja Lemke was largely local to Dortmund. On 21 January 2025 Radio 91.2 profiled the Die Linke candidate in Dortmund II as a 33-year-old computer scientist focused on housing and mobility: a rent cap and social housing, free local public transport, and more money for indebted Ruhr municipalities. She named Dortmund harbour as a favourite place and criticized sales of plots there to office investors. On 10 February 2025 the Ruhr Nachrichten posted a video interview of 6 minutes 42 seconds, headlined „Ich würde weniger gegen Menschen hetzen“ (“I would whip up less hatred against people”), reporting that she wanted more publicly built housing so rents would stay lower. A companion piece that day, headlined on making public transport free in the long run, listed questions on rents, the housing shortage, migration, extremism, her aims in Berlin, financing, and a political role model; the answers were not on the open page. The paper had already filmed a short “Schnellschuss” interview with her as candidate in constituency 143 on 22 September 2021.

After she took her seat, longer interviews were specialist rather than national-daily profiles. On 3 September 2025 Table.Briefings ran a summer interview by Nicola Kuhrt, “Die Hightech-Agenda lenkt von realen Problemen ab,” with Lemke as Die Linke’s research and technology spokesperson; the public summary says she criticized fixed-term research contracts, the Hightech Agenda, and closed sittings of the research committee. On 30 November 2025 nd-aktuell published an interview by Patrick Lempges in which she called the agenda a diversion from renewable energy, transport policy and social division. netzpolitik.org has quoted her in news reports, not a profile: on 6 October 2026, as spokesperson for digital administration and open government, she questioned undocumented meetings and vendor lock-in around the Deutschland-App, and the site tags further mentions. A 7 March 2026 taz article on that closed committee did not name her. These pieces record policy criticism, not personal controversy.

Online communication

Her Bundestag biography lists Bluesky (sonjalemke.dielinkebt.de), Instagram (sonja_lemke_) and Mastodon (@sonjalemke@ruhr.social). On abgeordnetenwatch.de, the 2025–2029 profile showed an 88 percent response rate, seven of eight questions in the current candidacy and mandate. Asked on 26 November 2025 whether she and the party should quit commercial platforms, given Die Linke’s use of TikTok, she answered on 8 December that those services still reached people otherwise missed, citing circulation of a speech by Heidi Reichinnek. She said Mastodon-style alternatives should come first, that material should also sit on websites without an account, and that posts should not be written only so algorithms “work.” On those terms she called a presence on the large platforms defensible, while urging stricter enforcement of the Digital Services Act, the Digital Markets Act and the EU AI Act.