Voters in Holborn and St Pancras will go to the polls on 8 October in a by-election triggered by the resignation of former prime minister Keir Starmer from parliament, following his ousting by the Labour Party and replacement by Andy Burnham.

We previously reported that the exact date for next month's contest was still to be finalised; according to reports on Friday, the poll has now been set for Thursday, 8 October.

Green Party leader Zack Polanski was formally confirmed as his party's candidate on Friday morning, setting up what is widely seen as a direct contest against Labour's Sagal Abdi-Wali. Polanski won an internal ballot of local members on Thursday night, defeating local Green councillor Hamza Chowdhury. Green MP Hannah Spencer said members had "overwhelmingly" chosen Polanski, after Chowdhury had argued during the selection that the area did not need an MP who "arrives during an election campaign" and then "disappears once the votes are counted".

Winning the seat will be a major challenge for the Greens. Labour has held Holborn and St Pancras continuously since the constituency was established in 1983, represented only by Frank Dobson and then Starmer, who defended it with an 11,572-vote majority at the 2024 general election.

However, the Greens are aiming to build on local gains. Polanski noted on Friday that his party grew from one councillor to 10 in the London Borough of Camden at the local elections in May, saying: "Everyone knows it's the Green Party against Labour... Greens might be the underdog in this election, but we have the momentum, and we can win."

Polanski also pointed to his personal ties to the constituency, saying: "I am proud and honoured to have been selected for a by-election in the constituency where I have lived and worked for much of the past 20 years. I love this place and so do the people whose doors I’ve knocked on in recent days – but it can be even better. I know times are tough in Holborn and St Pancras."

Labour is campaigning on the local government record of Abdi-Wali, who has been a councillor for Camden Square since 2022 and leader of Camden Council since May. Labour MP Liam Conlon, who is heading the party's campaign, said: "Only Labour’s Sagal Abdi-Wali is rooted in this community and has a proven track record of delivering for Camden. She has spent 20 years volunteering across this area, and taken action to improve housing and support for young families as council leader."

The by-election will provide an early test of public support for Burnham since taking office, while testing Polanski's momentum following a recent dip in national polling for the Greens.

Campaigning is already underway across the constituency ahead of polling day. I'll be following this race closely — check back for updates as it unfolds.