Zack Polanski joined by Councillor Hamza Chowdhury at the Green Party campaign launch

ZACK Polanski is telling voters that they do not need “another Labour MP” in parliament as he tries to make history in the Holborn and St Pancras by-election.

The Green Party leader was selected by local members to stand on Thursday and launched his campaign the next morning.

A key question for Mr Polanski is whether the recent rise of the Greens under the leadership had been fuelled by Sir Keir Starmer’s performance as prime minister – and whether the change at Downing Street will now alter the landscape again.

“Sir Keir Starmer’s unpopularity did help the Green Party – I think that’s completely true,” he said. “What I think it did was make people who had voted Labour previously to stop the Tories or whatever reason go ‘oh, there’s an alternative now. I don’t have to face the least worst option’.”

At the October 8 by-election, triggered by Mr Starmer’s exit, it has been claimed Labour can not convincingly tell Camden’s traditionally left-leaning electorate that the Tories or Reform could get elected by the back door if votes are split.

Mr Polanski said: “People have seen there is an alternative where you can vote for the Green Party knowing that we would reduce inequality, that we would lower people’s bills, would stand for peace and justice around the world. Keir Starmer’s gone but what hasn’t gone is people who have now opened their eyes and their ears to [the fact] that there are alternatives.”

He said there would be residents that wanted to give Mr Starmer’s successor a chance but he added: “Should Labour win this election, Andy Burnham will think the job’s done and just carry on the route of saying he’s going to end neoliberalism but ruling out rent controls or talking about drilling for new oil and gas in the North Sea.”

He said that as the first Green MP to be elected in London he could challenge the Labour government in a “constructive way”, adding: “We need to have rent controls, we need to build council housing, we need to make sure there’s justice for leaseholders – let’s nationalise Thames Water. I think all of these policies are on the table.”

Mr Polanski was a comfortable winner in his candidate selection contest with Camden councillor Hamza Chowdhury – and he invited Mr Chowdhury on to the stage of the campaign launch alongside a group of other Green figures including new MP Hannah Spencer and Baroness Natalie Bennett, who herself was once a candidate in Holborn and St Pancras.

He cited Baroness Bennett when asked whether losing to Labour here next month would be a risk for his own political career and the leadership of the party. “I don’t think it’s a big test for me,” he said. “This has previously been a strong Labour seat. It’s been held since 1983 and, and we’re at a time where we’ve got a new Prime Minister who’s experiencing a honeymoon. I think the fact that everyone on the doorsteps and pretty much the entire media recognises this is between the Labour Party and the Green Party and having a huge chance as the underdogs is actually already a success.

“In terms of some of the press who have got very excited about what does it mean for me, I would just say gently Nigel Farage ran for election eight times before he won an election. Two former leaders of the Green Party, Natalie Bennett and Sian Berry, both ran literally in Holborn and St Pancras and have gone on to do brilliant things.

“I would be disappointed not to win. I’m going to put everything into this election but I think it’s also very clear that this is a moment where the fact that we are credible challengers is actually a huge step up for the Green Party.”

Asked how he felt about the tags “populist” and “opportunist” that rivals attach to him – often mentioning his past time in the Camden Liberal Democrats – he said: “No one joins the Green Party in 2017 for an opportunity, with no disrespect to people who were in the Green Party at the time. I joined the Green Party because I had lots of debates, in fact the CNJ was at many of them, with Natalie Bennett and Sian Berry. I would often go home and, and say to my partner ‘I really agree with a lot of the things they’re saying ­– I think I might be in the wrong party’.

“The main thing is I don’t think it’s anything to be embarrassed by or ashamed for a single bit. I think one: it demonstrates how long I’ve cared about the area, and second: I think it demonstrates that people change their politics. They learn things. They adapt. They develop.”

Mr Polanski said he had solidarity with Labour opponent Sagal Abdi-Wali over the tweet posted by Reform’s Zia Yusuf over her life story as a child refugee from Somalia.

But he added that voters needed to separate that from the different parties’ policies, raising Mr Starmer’s infamous “island of strangers” speech and current home secretary Shabana Mahmood’s moves to make it harder to secure “indefinite leave to remain”.