Green Party leader Zack Polanski will face an internal challenge to become his party’s candidate in the by-election caused by Sir Keir Starmer leaving Parliament.

Local councillor Hamza Chowdhury, launching his own bid for the Green nomination, stated that Holborn and St Pancras does not need "another MP who arrives during an election campaign" and then "disappears once the votes are counted".

Mr Polanski had earlier described himself as "excited" by the possibility of winning the seat to take a place in Parliament.

The nominee will be chosen by local Green Party members for a contest that may test Prime Minister Andy Burnham’s public popularity, as constituency voters have increasingly favoured Green and independent candidates over Labour in recent years.

Mr Chowdhury argued that a "global majority" candidate would be best positioned to win and represent the "extraordinary diversity of the communities" in the seat.

The Camden councillor said: “We don’t need another MP who arrives during an election campaign, puts out a few leaflets, makes a few promises and disappears once the votes are counted.

“We need an MP who is present, accessible and visibly part of the community all year round.”

Mr Chowdhury, who represents the Holborn and Covent Garden ward, said: “I’m not asking you to vote for a politician you’ll only see on a leaflet.

“I’m asking you to choose someone who is already here.”

Mr Polanski, a London Assembly member, announced his hope to contest the seat and win a place in Parliament to the last week.

“I have lived and worked in this community over many years, I know it well and I love it,” Mr Polanski said in an interview with the north London newspaper.

“It represents so many of the things that make London so special.

“I am so excited by the prospect of representing this place in Parliament.”

Green Party members in the seat are expected to decide on their candidate on Thursday, with the result announced on Friday.

The Greens are likely to pose the greatest threat in the by-election to Labour, which has held the inner London constituency continuously since the seat was created in 1983, winning at least 40 per cent of the vote at every election.

Only two Labour MPs have ever represented Holborn and St Pancras: former health secretary Frank Dobson, from 1983 to 2015, then Sir Keir.

At the most recent general election in 2024, Sir Keir held the seat with 48.9 per cent of the vote, ahead of independent candidate Andrew Feinstein in second place on 18.9 per cent and the Greens in third on 10.4 per cent.

The Conservatives came fourth on 7.2 per cent, Reform finished fifth on 6.1 per cent and the Liberal Democrats were sixth on 5.8 per cent.

The popularity of the independent and Green candidates at the 2024 contest, finishing second and third respectively, may have been partly down to former Labour voters protesting against Sir Keir’s refusal to take a stronger position on Israel’s actions in Gaza in the war with Hamas.

The Green Party also made gains in the May local elections in the London Borough of Camden, the local authority which covers the constituency.

A date for the Holborn and St Pancras by-election has not yet been set.