Siân Berry

MP for Brighton Pavilion

Green

Siân Berry is the Green Party MP for Brighton Pavilion, having first been elected to parliament at the 2024 general election.

In the 2024 general election, Berry won 28,809 votes, representing 55.0% of the vote. The Labour Party candidate,Tom Gray, received 14,519 votes (27.7%), while the Conservative candidate, Sarah Webster, secured 3,975 votes (7.6%). Berry was duly elected with a majority of 14,290.

The Brighton Pavilion constituency is located in the city of Brighton and Hove, East Sussex, in the South East England region. It covers the central and northern parts of Brighton.

The seat has been held by the Green Party since 2010, when Caroline Lucas became the party’s first MP. Lucas secured 31.3% of the vote in Brighton Pavilion, defeating the incumbent Labour MP, David Lepper, and overturning a notional Labour majority of over 5,000.

In 2024, Berry successfully defended Brighton Pavilion following Lucas’ retirement.

In her 2024 maiden speech, Berry said Brighton has long been “at the heart of the green movement in England and Wales, and that continued when our own, beloved Caroline Lucas won the seat for the Green Party in 2010.”

Political Career

Berry currently serves as the Green Party’s spokesperson in the House of Commons for crime and policing, justice, transport, work and pensions, culture, media and sport, and democratic standards (all since July 2024).

Berry is listed as a member of the all-party parliamentary groups (APPGs) for council and social housing, eating disorders and humanism.

Berry delivered her maiden speech in the commons on 17 July 2024 in a debate on the king’s speech.

In it, she said: “Listening to people in my constituency during the election, it was hard not to be affected by the strength of public feeling and distress about the climate emergency and the degradation of our natural environment, and by the huge desire to defend social justice and public services. This Parliament must seek to deliver for them.”

She added: “Our 16 and 17-year-olds, and our young people, need a real voice and need those measures in this parliament. I hope that, when we debate the bills put forward in today’s King’s Speech, the voices of young people are sought out and listened to, and that many changes and additions are made where they are needed most, including removing the two-child benefit cap.”

Berry has been a leading figure in the Green Party for decades. She served as co-leader of the Green Party of England and Wales (GPEW) alongside Jonathan Bartley from September 2018 to October 2021.

In the 2018 Green leadership election, Berry and Bartley won with 75.5% of the vote in round one.

Berry and Bartley led the Greens into two national elections in 2019. The first, the European Parliament elections, were dominated by Brexit as the campaign’s central, defining issue. The Greens, alongside the Liberal Democrats and new Brexit Party, benefitted from a deep public backlash against the two main parties. Green parties collectively secured their best-ever national result in Britain, winning more than two million votes (12.1%) and seven seats (up four).

At the 2019 general election, the Greens embraced a limited election pact with Plaid Cymru and the Liberal Democrats, which saw the parties stand aside in dozens of constituencies to boost their partners’ chances. The deal covered 60 constituencies across England and Wales. The Green Party’s manifesto for the 2019 general election endorsed a “people’s vote” or second Brexit referendum. The party’s vote share rose modestly to 2.7%, but it once again failed to secure a second MP.

In July 2021, Berry cited the party’s internal dispute over gender identity and sex-based rights among her reasons for stepping down as co-leader of the GPEW. Berry warned that she could “no longer make the claim” that the Green Party fully backed trans rights, following “the party’s choice of frontbench representatives”.

Berry was reportedly referring to Shahrar Ali, who served as a Green deputy leader from 2014 to 2016. In June 2021, Ali was appointed as the Green Party’s spokesperson for policing and domestic safety.

Ali, during his campaign for the Green Party leadership in 2020, released a statement which said that women were commonly defined as “an adult human female and, genetically, typified by two XX chromosomes”.

In March 2021, the Green conference voted in favour of gender self-identification.

Ali stood for Green Party leadership election for a third time in 2021, placing third with 2,422 votes. During his 2021 leadership bid, Ali called for “a culture of open debate, where the taking of offence is not used as a means to prevent those who do wish to debate from doing so”.

In October 2022, members of the Scottish Green Party voted to suspend ties with the GPEW until the latter addressed “both issues of transphobia and respect for the Scottish Green Party”. The relevant motion claimed that disciplinary action from GPEW had been “lethargic, ineffective and inconsistent”.

Berry said she was saddened by the decision but added the party had “many problems left to solve”.

Berry was a member of the London Assembly (MLA), representing the Green Party as a London-wide list member, from May 2016 until May 2024. She also served as a Green Party councillor on Camden London Borough Council from 2014 to 2022.

Berry has stood as the Green Party candidate for mayor of London three times, in 2008, 2016 and 2021. In the 2008 London mayoral election, Berry placed fourth with 77,347 votes (3.2%).

Berry stood for parliament in Hampstead and Highgate at the 2005 general election and Holborn and St Pancras in the 2017 general election.

Previously, Berry served as the party’s woman principal speaker from 2006 to 2007. She supported the transition to the Greens’ current leadership model in a landmark 2007 internal referendum, in which party members voted to replace the “principal speaker” system with a formal leader and deputy leader structure.

Writing in the New Statesman in March 2007, Berry argued that the absence of a clear figurehead had become a “barrier to communicating with people”. In the event, 73% of members backed the creation of the leader and deputy leader positions – achieving the necessary two-third majority.

Political views

The Greens are an environmentalist and progressive political party positioned on the left of British politics.

The party’s foundational ideological beliefs are set out in its official core values and “philosophical basis”. This latter document outlines the aims and beliefs of the party, providing the basis on which all its policies are agreed.

The opening to the Green Party’s philosophical basis states: “A system based on inequality and exploitation is threatening the future of the planet on which we depend, and encouraging reckless and environmentally damaging consumerism.

“A world based on cooperation and democracy would prioritise the many, not the few, and would not risk the planet’s future with environmental destruction and unsustainable consumption.”

The Greens’ 10-point statement of core values commits the party to “social and environmental justice, which supports a radical transformation of society for the benefit of all, and for the planet as a whole.”

The party’s 2024 general election manifesto, branded with the slogan “Real hope. Real change”, focused heavily on the cost of living and affordability.

Berry is listed as one of activist group Green New Deal Rising’s “cross-party green new deal champions”. GNDR is a progressive campaign organisation which promotes rapid decarbonisation and the transformation of the UK economy with a “Green New Deal” – a long-term plan to tackle climate change with large-scale public investment in renewable energy, green infrastructure and public services.

Berry was endorsed by local groups of the cross-party organisation Compass during the 2024 general election. Compass is a thinktank and campaign group. As part of its “Win as One” campaign in the 2024 election, local Compass groups backed a slate of progressive candidates who had pledged their support for electoral reform. The central aim of the initiative was to elect a “caucus” of MPs who would champion the cause of replacing the first past the post (FPTP) electoral system.

Brexit and Europe

Left-wing ‘people’s vote’: In March 2019, Berry was among 20 signatories to a cross-party letter published in the Guardian that called for a second referendum and rubbished Brexit as a “massive assault” on working-class people.

The letter read:“We are campaigning to transform society, not for the status quo. We are against Brexit because it is a massive assault on working-class people, on the environment, on migrants and on the communities that the left aims to represent.”

Customs union vote (2025): In December 2025, Berry voted in favour of the UK-EU Customs Union (Duty to Negotiate) Bill. The bill, introduced under the 10-minute rule procedure by Liberal Democrat Europe spokesperson Al Pinkerton, sought to mandate the government to enter into negotiations with the European Union to establish a bespoke customs union. In total, 13 Labour MPs joined the Liberal Democrats in supporting the motion, while the majority of the party abstained.

Electoral reform

Fair elections APPG: Berry is listed as a member of the all-party parliamentary group (APPG) for fair elections – a cross-party group of MPs and peers that campaigns for electoral reform. The group’s stated aims include replacing the first past the post (FPTP) voting system with a form of proportional representation, eliminating “dark money” and “undemocratic influence” from politics, and countering disinformation.

Electoral reform amendment: In May 2026, Berry signed an amendment to the Representation of the People Bill, calling on the government to establish a “national commission on electoral reform”. Tabled by Alex Sobel as chair of the fair elections APPG, the amendment aimed to force a rethink of the first past the post voting system.

At the time, Sobel described FPTP as “one of the biggest examples of a broken status quo in UK politics.” He invited colleagues to join this “common sense call to take a fresh look at how parliament is elected in modern Britain.”

Proportional representation bill: In December 2024, Berry voted in favour of the Elections (Proportional Representation) Bill – introduced by Liberal Democrat frontbencher Sarah Olney under the 10-minute rule procedure. The bill sought to “introduce a system of proportional representation for parliamentary elections and for local government elections in England”.

A total of 138 MPs supported the bill – with 136 opposed. Notably, 59 Labour MPs backed Olney’s bill.

Introducing the bill, Olney told the House: “First past the post is a broken and unfair system. This summer, the Labour party won a landslide election victory, securing 63% of seats in the House of Commons in return for just 34% of the vote.

“The system leaves millions of voices unheard and creates a divisive, adversarial political climate where collaboration is discouraged and accountability is often sidestepped.”

Welfare

Winter fuel payment EDM: In September 2024, Berry signed an early day motion (EDM) expressing concern over the government’s proposed changes to the winter fuel payment. The motion called on the government to “postpone the ending of winter fuel payments and establish a comprehensive strategy to tackle fuel poverty, health inequality and low incomes among older people.”

Assisted dying

Berry voted in favour of the Terminally Ill Adults (End of Life) Bill, better known as the assisted dying bill, at both second reading (November 2024) and third reading (June 2025).

Social values and conscience issues

Abortion decriminalisation (2025): Berry voted in favour of a backbench amendment to the Crime and Policing Bill that sought to decriminalise abortion in England and Wales in June 2025. The amendment, which was passed by a majority of 242 votes, removed women from the threat of prosecution for ending a pregnancy at any stage. As an issue of conscience, MPs were allowed to vote according to their personal beliefs.

Lying amendment: In January 2026, Berry was listed as a supporter of an amendment to the Public Office (Accountability) Bill, often referred to as the “Hillsborough Law”, that would extend the proposed criminal offence of misleading the public to include MPs and peers. Luke Myer, the Labour MP behind the proposal, argued that his amendment would mean “no-one in parliament would be above the law”, adding: “If politicians deliberately lie to the public, there should be consequences.”

Myer stated: “This amendment is a proportionate, carefully safeguarded response to a real democratic risk. It is not about stifling debate or political disagreement, it is about ensuring that those who seek or hold public office cannot deliberately and knowingly mislead the public without consequence.

“The polling shows that voters across the political spectrum expect parliament to act.”

Myer’s amendment won the support of 30 cross-party MPs.

Palestine

Palestine Action vote: In July 2025, Berry was one of 26 MPs to vote against the proscription of Palestine Action under the Terrorism Act 2000. The ban, passed by 385 votes to 26, came after the Home Office accused the group of “aggressive and intimidatory attacks against businesses, institutions and the public”. However, civil liberties organisations argued proscription represented an overreach of state power and a threat to the right to protest.

Before Politics

Born Siân Rebecca Berry on 9 July 1974 in Cheltenham, Gloucestershire, she attended Pate’s Grammar School in Cheltenham. She studied metallurgy and the science of materials at Trinity College, Oxford, graduating in 1997.

After university, Berry worked for several years as a medical copywriter.

Berry later worked as an author and editor, contributing to books such as 50 Ways to Greener Travel (2008).