A fourth newly elected Green Party councillor in London has quit, leaving taxpayers with a £80,000 bill.
New Green representatives on Camden, Haringey, Lambeth and Hackney councils have immediately stood down, meaning by-elections will have to be held.
Each poll is expected to cost the local authorities between £20,000 and £25,000.
A Labour Party spokesperson said: “The Greens can’t be trusted to deliver at your local council. Now their incompetence will come at a huge cost to taxpayers everywhere.”
Saiqa Ali was elected as one of 29 Green councillors in Lambeth on May 7, despite her arrest in the lead up to the polls over allegations she had made a series of antisemitic social media posts.
She was suspended from the party and it was revealed on Thursday night that she has decided not to take up her seat in the Streatham St Leonard ward.
The Greens said before the election that it was too late to remove her from the ballot due to electoral law.
James Tilden was elected to represent Hackney Central ward with 1,681 votes following the council elections last Thursday, but his party failed to realise this breached electoral law before making him a candidate because he is a primary school teacher who works for the local authority.
Muhammed Naser, who was elected in the Regent's Park ward of Camden council, has also had to stand down for the same reason.
Jayon Henriques was elected to represent Northumberland Park ward in Haringey but it has since been revealed he is also ineligible to be a councillor. The party has not revealed why he cannot serve in the town hall.
A Haringey Greens spokesman said: “As soon as we were made aware we informed the Electoral Commission and Haringey Council returning officer, and followed their instructions. No local campaigning took place in the ward.”
They added: “We accept the candidate made an error in good faith regarding his eligibility. A by-election will be announced in due course and we look forward to campaigning with a new candidate.”
Labour has lost control of more than half of its London boroughs in a dire set of elections for Sir Keir Starmer and his premiership last week.
Zack Polanski’s Green Party were the main beneficiaries from Labour’s plummeting popularity in the capital, taking control of Lewisham, Hackney and Waltham Forest in a series of historic wins.
Meanwhile, Brent, Enfield, Haringey Southwark and Lambeth fell to no overall control after decades of Labour rule.
A Labour party spokesman added: “Whether it’s teaming up with the Tories to oppose new homes in Enfield, or their leader Zack Polanski misleading the public over his failure to pay council tax – the Greens are showing they won't do the right thing for Londoners.
“Labour will continue to work hard and deliver for residents across the capital. Because the Greens simply aren’t up to the task.”
