Zack Polanski has confirmed he will stay on as leader of the Green Party after finishing second in the Holborn and St Pancras by-election, a contest triggered by Sir Keir Starmer's departure from the Commons. Labour's Sagal Abdi-Wali won the seat, but the Green Party's near doubling of its vote share has reshaped the conversation around the party's direction and Polanski's leadership.
A by-election with symbolic weight
Holborn and St Pancras was never going to be a routine contest. It was the former seat of a sitting prime minister, making it a proxy battleground for parties keen to signal momentum or decline. Abdi-Wali took the seat with 45.17% of the vote, a drop of nearly four points on the previous result, while Polanski's Greens surged by more than 22 points to finish on 32.81%. Reform UK, the Conservatives and the Liberal Democrats all saw their shares fall or stagnate, underlining how the contest became largely a two-way story between Labour and the Greens in this constituency.
Polanski rejected any suggestion that contesting the seat had been a misstep. Asked directly whether he regretted standing, he told Sky News it had given him a platform to put Green policies - rent controls, climate action and the nationalisation of Thames Water - in front of voters. That framing matters: a strong second-place finish, even in defeat, can be presented as evidence of a party building a national profile rather than one overreaching.
Leadership scrutiny after a high-profile defeat
Leadership challenges after a lost by-election are common across British politics, and Polanski faced the question squarely. His answer - "Yes absolutely. That is what leaders do" - was unambiguous. Whether that position holds depends on how Green members and the wider public interpret the result. A doubled vote share in a seat vacated by a former prime minister is, on its own terms, a credible result for a smaller party, even if it falls short of outright victory.
The by-election also arrived days after Green members passed a contested conference motion describing Zionism as a form of racism. Polanski addressed this directly when pressed by broadcasters, distinguishing between criticism of the Israeli state and antisemitism, and arguing the two should not be conflated. This is a politically sensitive area, and his comments reflect an attempt to hold together a coalition of members while managing concerns raised by Jewish community organisations about the language used.
What the new MP represents
Sagal Abdi-Wali's victory carries its own significance beyond the party arithmetic. The former leader of Camden Council, and the borough's first black female leader, she arrived in the UK as a child refugee from Somalia. Her campaign focused on housing and homelessness, issues she has worked on directly through her council role, and she has pledged to prioritise action on rough sleeping as one of her first acts as MP.
Her win also became a flashpoint after comments from Reform UK's Zia Yusuf about her country of birth were widely condemned, including by a government minister, as racist. Abdi-Wali's victory speech leaned into this directly, framing her win as a rejection of division and an endorsement of a campaign built on community ties rather than grievance politics. For a constituency as diverse as Holborn and St Pancras, that framing is likely to shape how her tenure is read by both supporters and critics in the months ahead.