Green Party leader Zack Polanski has been formally selected to fight the Holborn and St Pancras by-election, setting up a high-profile contest with Labour for the parliamentary seat vacated by former prime minister Sir Keir Starmer.
Polanski was confirmed as the Greens' candidate on Friday after defeating Camden Green councillor Hamza Chowdhury in a vote of local party members.
The by-election will take place on 8 October and is shaping up as an early electoral test for Prime Minister Andy Burnham as the Greens attempt to capitalise on recent gains in the capital.
Polanski says Greens can win
Speaking after his selection, Polanski acknowledged that Labour begins the campaign with the advantage but insisted the Greens could pull off an upset.
He said: “The Greens might be the underdog in this election, but we have the momentum and we can win.”
Polanski pointed to the party's rapid expansion on Camden Council, saying the Greens had gone from one councillor in the area before May's local elections to 10.
He has previously described the contest as a “referendum on ending Rip-off Britain”, arguing that the party can offer voters a left-wing alternative to Labour.
Local members choose party leader
Polanski's selection was not automatic despite his position as national Green Party leader.
He faced a challenge for the nomination from Chowdhury, a local councillor who had argued that Holborn and St Pancras did not need another MP who arrived during an election campaign and then disappeared after polling day.
Polanski defended his local connections during the selection contest, saying he had lived in the constituency after moving to London around 20 years ago and continued to know the area well.
Local Green members ultimately selected Polanski following hustings held on Thursday.
Labour selects Sagal Abdi-Wali
Labour has selected Sagal Abdi-Wali, leader of Camden Council, to defend the seat.
Abdi-Wali came to Britain with her family as a child refugee from Somalia and has described how the area welcomed her family and gave them hope after they fled conflict.
She has served as a Camden councillor since 2022 and became leader of the council in May 2026.
Prime Minister Andy Burnham has already visited the constituency to campaign alongside Labour's candidate.
Starmer won comfortably in 2024 – but vote share fell
Sir Keir Starmer retained Holborn and St Pancras at the 2024 general election with 48.9% of the vote, giving Labour a majority of more than 11,000.
Independent candidate Andrew Feinstein finished second with 18.9% after campaigning heavily over Israel's actions in Gaza, while the Green candidate took 10.4%.
Feinstein has ruled himself out of the forthcoming contest, potentially leaving both Labour and the Greens competing for voters who backed him in 2024.
The constituency has been represented by Labour continuously since it was created in 1983, first by Frank Dobson and then by Starmer from 2015.
Greens strengthened position in Camden
The Greens enter the parliamentary contest after making substantial gains in Camden at the May local elections.
Polanski said the party now has 10 councillors in the area, compared with only one before those elections.
That local growth has encouraged the Greens to treat Holborn and St Pancras as a realistic target despite Labour's historic strength in the constituency.
Early test for Burnham
The result will provide an early indication of whether Labour's change of leadership under Andy Burnham has halted the loss of support to parties on its left.
Polanski became Green Party leader in September 2025 and has overseen significant growth in party membership and a series of electoral advances, including the Greens' breakthrough parliamentary by-election victory in Gorton and Denton.
A victory in Starmer's former constituency would give Polanski a seat in the House of Commons and represent another major breakthrough for the party.
Labour, meanwhile, will be determined to demonstrate that Burnham's arrival in Downing Street has strengthened its position among voters who had become dissatisfied during Starmer's premiership.
High-profile battle begins
With Polanski now formally selected, the contest has moved from speculation to a direct battle between the Green leader and Labour's local council leader.
Polanski insists the Greens have the momentum to overcome Labour's sizeable 2024 majority, while Labour will seek to retain a constituency it has held for more than four decades.
Voters in Holborn and St Pancras will deliver their verdict on Thursday 8 October.