The Green Party of England and Wales introduced its first elected party leader in 2008, replacing its earlier principal-speaker system. This timeline follows each leader and co-leadership team through to the present day.
The party traces its roots to the PEOPLE party, founded in 1972, later renamed the Ecology Party and then the Green Party. The Green Party of England and Wales became a separate organisation in 1990. This timeline covers the formal leadership posts introduced in 2008, rather than attempting to treat the earlier principal speakers as equivalent to party leaders.
See also: UK Conservative Party Leaders Timeline | UK Labour Party Leaders Timeline | UK Liberal Democrat Leaders Timeline.
Timeline Contents (Tap to jump down the page!) |
First Elected Leaders (2008–2016) |
Co-Leadership and the Return to a Single Leader (2016–Present) |
First Elected Leaders (2008–2016)
5 September 2008 – 3 September 2012 – Caroline Lucas
Caroline Lucas became the first elected leader after members voted to replace the principal-speaker arrangement with a formal leadership position. In 2010, she became the first Green Party MP elected to the House of Commons, representing Brighton Pavilion.
Prime Ministers: Gordon Brown (Labour Party), 2008–2010; David Cameron (Conservative Party), 2010–2012.
3 September 2012 – 2 September 2016 – Natalie Bennett
Natalie Bennett succeeded Caroline Lucas and led the party through the 2015 UK general election. The Greens retained Brighton Pavilion and continued to campaign on environmental and social policies.
Prime Ministers: David Cameron (Conservative Party), 2012–2016; Theresa May (Conservative Party), 2016.
Co-Leadership and the Return to a Single Leader (2016–Present)
2 September 2016 – 4 September 2018 – Caroline Lucas and Jonathan Bartley (Co-leaders)
Caroline Lucas returned to the leadership alongside Jonathan Bartley. Their joint election marked the first period of formal co-leadership in the party’s history.
Prime Ministers: Theresa May (Conservative Party).
4 September 2018 – 31 July 2021 – Siân Berry and Jonathan Bartley (Co-leaders)
Siân Berry and Jonathan Bartley were elected as co-leaders in 2018 and re-elected in 2020. Bartley resigned in July 2021, leaving Berry to serve briefly on her own until the next leadership election.
Prime Ministers: Theresa May (Conservative Party), 2018–2019; Boris Johnson (Conservative Party), 2019–2021.
31 July 2021 – 1 October 2021 – Siân Berry (Interim sole leader)
Following Jonathan Bartley’s resignation, Siân Berry continued as the remaining leader during the party’s leadership transition. She had announced that she would not stand in the next leadership election.
Prime Ministers: Boris Johnson (Conservative Party).
1 October 2021 – 2 September 2025 – Carla Denyer and Adrian Ramsay (Co-leaders)
Carla Denyer and Adrian Ramsay were elected as co-leaders in 2021. Both won parliamentary seats at the 2024 UK general election, when the Greens secured four seats in the House of Commons. Denyer later decided not to seek another leadership term.
Prime Ministers: Boris Johnson (Conservative Party), 2021–2022; Liz Truss (Conservative Party), 2022; Rishi Sunak (Conservative Party), 2022–2024; Keir Starmer (Labour Party), 2024–2025.
2 September 2025 – Present – Zack Polanski
Zack Polanski won the September 2025 leadership election and replaced the co-leadership team of Carla Denyer and Adrian Ramsay. He had previously served as the party’s deputy leader and is a member of the London Assembly.
Prime Ministers: Keir Starmer (Labour Party), 2025–20 July 2026; Andy Burnham (Labour Party), 20 July 2026–present.
Researched and updated 19 October 2026. Leadership and current-office details reflect information available on that date.