An ex-Labour councillor who defected to the Greens said her old party had "let down" the area over the O2 regeneration.

Former Fortune Green councillor Lorna Russell hoped to return to Camden's council chamber in Thursday's South Hampstead by-election.

But she came fourth with 295 votes, as social worker Tommy Gale held the seat for Labour with 882 votes, the Conservatives polling second with 766 cites, and the Liberal Democrats third with 531.

Nonetheless, the former cabinet advisor said the planned 02 Centre regeneration project spanning West Hampstead and Swiss Cottage, approved by Labour councillors in March, was the biggest issue on the doorstep.

"Labour's let down the area," she said. "I used to be a Labour councillor, I was told off, and this is on record, for taking an early opposition to the 02 centre.

"I was the only person to vote against the 02 Centre, and (former councillor) Will Prince did but he had the freedom to do that as he was leaving."

First elected to Camden Council as a Labour councillor in 2014, she was appointed cabinet advisor in 2019 before defecting to the Green Party in 2021.

Explaining why she joined the Greens, she said: "We stand for affordable housing, we stand for green spaces and we stand for listening to the results of a consultation, and that's one of the reasons I left the party."

Labour holds 46 of the 55 seats in the borough and Cllr Siân Berry, who represents Highgate, is currently the only elected Green Party member.

Ms Russell said there were things that "people don't realise" about having an extra Green councillor in the chamber - including the power to hold the ruling Labour group to account.

She added: "Having one councillor is amazing, but Siân by herself is not allowed to sit on any scrutiny committees, she does not have the ability raise a budget, she does not have the ability to propose a motion and pick it up."

She said with a proportional system, and two Green councillors representing 4% of the total, they would be able to achieve far more.

"It's raising issues that matter to people and scrutinise in the most effective way possible," she added.