Green Party leader Zack Polanski has admitted he may have failed to pay the correct council tax while living on a London house boat.
Mr Polanski had faced mounting questions over whether the houseboat, moored in east London, was his primary residence.
The party originally said he only stayed on the boat “occasionally” but then issued an apology from Mr Polanski late on Monday night for what it called an “unintentional mistake”.
It comes after the London Assembly member also admitted he was wrong to previously describe himself as a spokesperson for the British Red Cross.
Labour said Mr Polanski “cannot be trusted” while the Conservatives accused him of “staggering hypocrisy”.
A Conservative member of the London Assembly has asked City Hall to look into whether he has breached conduct rules.
The Times last week reported seeing an advertisement for the sale of the boat in which Mr Polanski’s partner wrote: “We are moving to a house and so will sadly be leaving the gorgeous community behind.”
The Daily Mail separately reported that Mr Polanski was registered to vote at a building near the marina, which he is also said to have used as a mailing address.
Tax lawyer Dan Neidle, founder of Tax Policy Associates, analysed Mr Polanski’s situation this week and wrote: “If the boat was in fact Mr Polanski’s ‘sole or main residence’ then he and/or his partner should have registered for, and paid, council tax for those three years.”
A Green Party spokesperson said late Monday: “Until relatively recently, Zack was living on a houseboat, which came with its own unique practical circumstances and considerations.
“He has immediately taken steps to pay any council tax he may be found to owe. Zack apologises sincerely for the unintentional mistake.
They added: “For security reasons, we do not comment publicly on Zack’s address.
“There have recently been two serious incidents which have been reported to the police and are under investigation.”
The Green Party previously told The Times newspaper Mr Polanski rented a room at another address where council tax was included in the rent and only stayed on the boat “occasionally”.
Government guidance states that a person may be liable for council tax on a boat if it is their “sole or main” residence.
London Assembly member Neil Garratt has asked City Hall authorities to formally investigate the claims.
In a letter outlining his formal complaint, Mr Garratt asked for an assessment of whether Mr Polanski might have breached the Greater London Authority Code of Conduct.
Mr Garratt said in a statement: “People rightly expect senior politicians to follow the rules and pay the taxes they impose on others.
“If Mr Polanski paid all his council tax, why is he refusing to answer direct questions about when and where he paid it? I have asked the City Hall authorities to formally investigate these claims, as the public has a right to know the truth.”
Mr Polanski has overseen a surge in support for the Greens since he took over as leader last year, but has recently come under increased scrutiny over past statements.
Last week he acknowledged he was wrong to say he was a spokesperson for the British Red Cross, a claim he made as he campaigned to become the party’s deputy leader back in 2022.
He told the BBC he had hosted fundraisers for the charity, adding: “I used the wrong word, and I accept that, but I would essentially take words on stage with me and speak.”
The Labour Party said the Green leader had been “caught red-handed”.
“After repeatedly claiming his council tax was all above board, Zack Polanski has been caught red-handed,” it said.
“The Green Party leader has already been found out for fibbing over his employment history, and his hypnosis skills, and now this has emerged too. What else is Polanski hiding?
“This pattern of misleading the public shows Zack Polanski simply cannot be trusted.”
Conservative Party chairman Kevin Hollinrake said: “This is staggering hypocrisy from Zack Polanski. A man who wants to hike taxes for millions has failed to pay his own council tax properly.
“Zack Polanski cannot lecture families across the country about paying more when he apparently wouldn’t even meet his own obligations in full.
“The British public will see this for exactly what it is. One rule for Zack Polanski, another for everyone else.”
Waltham Forest council was contacted for comment.
