The spokesperson said earlier on Thursday that Polanski had faced “heightened intrusion and safety risk” and had been “the target of antisemitic and homophobic abuse” since becoming leader, adding that there had been two arrests related to “abuse directed towards him”.
Polanski ultimately failed to register to vote as a result of the security concerns and the “extra process” required to register to vote anonymously, the spokesperson said.
Earlier this week, the Green Party admitted that Polanski may have failed to pay council tax while living in a houseboat moored in an east London marina.
A resident of a boat is liable to pay council tax when it is used as their sole or main residence, experts say.
In an advertisement to sell the boat, Polanski’s partner described it as “our amazing home… for three years”.
When the BBC asked the Green Party for clarification, a spokesperson said: “Until relatively recently, Zack was living on a houseboat, which came with its own unique practical circumstances and considerations.”
The party told the Times that Polanski lived in a room at a different London address, where he paid council tax, and had only stayed on the boat “occasionally”.
“I thought I had been paying monthly mooring fees and I presumed the council tax would be included in that,” Polanski told broadcasters on Thursday.
“I also take responsibility – it’s up to me to make sure that I pay the tax that I owe,” he said. “It’s still not clear if I owe council tax or not. I’ve been in touch with the council.
“Even if it turns out I don’t owe anything, I will still pay the appropriate amount, because of the principle.”
The marina falls under Waltham Forest borough council, where Polanski had last been registered to vote. The last address at which he was registered to vote was a building near the marina.
A Waltham Forest Council spokesperson said it was assessing and taking legal advice over “complex factors unique to moorings”.