Siân Berry — British Green Party politician and London public figure

Political career and roles

Berry served as one of the Green Party's Principal Speakers in 2006–2007 and later became Co‑Leader of the party on 4 September 2018, serving alongside Jonathan Bartley. She stepped down from the party leadership in October 2021. She is a member of the London Assembly and is the Green Party councillor representing Highgate on Camden Council. Her profile combines grassroots campaigning with roles in city‑level governance.

Policy priorities and public positions

Berry's platform emphasises urgent action on climate change, investment in public and active transport, and measures to improve housing affordability and tenant rights. She frequently frames environmental policy alongside social justice, arguing that low‑carbon transitions must be fair and accessible. In London debates she has highlighted the need for better cycling infrastructure, stronger public transport funding and measures to reduce pollution in urban neighbourhoods.

Electoral history and campaigns

• Green Party Principal Speaker (2006–2007).
• Candidate for Mayor of London in 2008 (2008 mayoral election).
• Mayoral candidate again in 2016, when she finished third (2016 mayoral election).
• Co‑Leader of the Green Party of England and Wales (2018–2021).
• Member of the London Assembly and councillor for Highgate on Camden Council.

Notable facts and public image

Berry is often regarded as one of the Green Party's most prominent public faces in London, combining electoral campaigning with policy work and local representation. Her approach tends to stress practical urban measures—transport, housing and air quality—alongside national climate policies. She has been involved in multiple citywide campaigns and debates and continues to be a visible advocate for environmental and social reforms.

For more information about her party roles, public statements and campaign materials consult party pages and official election records linked above.