Zack Polanski is now viewed as weak, unpatriotic and untrustworthy by London voters, leaked Labour polling appears to show.
The internal polling – obtained by – shows the Green Party leader’s personal ratings in the capital have fallen into the red since the beginning of the year.
The new figures come after Polanski is campaigning to be the Green candidate in the upcoming Holborn and St Pancras by-election.
Local party members are deciding tonight who will challenge Labour in the London seat after Sir Keir Starmer quit Parliament at the start of the month.
Polanski, who became leader of the Green Party in September 2025, enjoyed high London approval ratings in the first few months that followed, according to Labour’s poll.
But it seems his popularity on key leadership qualities has tanked in the capital after a string of controversies this year – although he is substantially more popular in London than in the country as a whole.
The leaked research shows Londoners widely thought the current City Hall councillor was competent and on the people’s side in December last year, with net ratings of more than 20%.
He also had net positive ratings for being strong, trustworthy and patriotic.
But in the eight months from December to August 2026, Polanski’s ratings on these key markers appear to have steadily fallen, according to the internal Labour poll.
Substantially more Londoners now see the Green Party leader as weak compared to those who see him as strong, by a net 22%.
Polanski also has net negative rankings for being unpatriotic, untrustworthy and incompetent.
His highest marker – being on the side of ordinary working people – has fallen from above 30% net positive to -8% negative.
And it’s not just Londoners who have a lower opinion of the Green leader – it’s a similar story across the UK.
The leaked poll suggests, however, that voters outside the capital already had a net less favourable view of Polanski when it came to his trustworthiness, strength, or the degree to which he is out of touch.
Public YouGov polling suggests that Polanski was more popular than unpopular across the country until May this year.
The switch coincided with a terror attack in Golders Green, north London, after which Polanski reposted an X post which criticised police officers for kicking the head of the stabbing suspect to get him to drop his knife.
Polanski, who is Jewish, later apologised after being rebuked by the Metropolitan Police Commissioner Sir Mark Rowley and the Prime Minister.
The Green Party leader sparked another row in July when he ‘inadvertently’ shared an image of a man wearing a T-shirt displaying the words ‘We’re only making plans for Nigel’ and an image of a guillotine.
Despite this, the Green Party remains a popular force in London, having won three councils and two mayoralties in the local elections in May.
Metro understands that Labour’s internal polling matches public surveys on voter intention in the capital, which last showed Labour on 27% and the Greens on 17%.
Polanski is hoping to capitalise on the Green surge by standing in the Holborn and St Pancras by-election.
The borough’s leader, Sagal Abdi-Wali, was elected as Labour’s candidate on Wednesday evening.
The Green candidate will be confirmed on Friday.
Labour won the seat by 11,000 votes in 2024, but the party has fallen in popularity since then.
A Polanski challenge will be Andy Burnham’s first electoral test since becoming Prime Minister six weeks ago.
The Green Party also made large gains in Camden in the local elections, growing from one to 11 councillors.
A Green Party spokesperson said: ‘We’d like to thank Labour for providing us with free polling, which shows we’re the main challenger in one of their safest seats. We may even put it on a leaflet.
‘We have been out and about in Holborn and St Pancras, campaigning for a Green MP, and are getting a very positive hearing for our plans for rent controls and affordable housing.’
Get in touch with our news team by emailing us at webnews@metro.co.uk.
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