Senior Labour politicians across London have warned the government not to take progressive voters for granted, with concerns the party faces a “political earthquake” in the capital in May after a surge in support for the Greens.
They have been privately circulating new data that suggests Labour could drop from first to fourth place in London in the May elections – losing control of all but two of their councils – with the Greens soaring into first place to take nine.
“The government needs to demonstrate that they’re not taking liberal, progressive voters in the capital for granted,” a senior London Labour figure warned.
Another added: “It’s going to be a total catastrophe for us in London. If we lose swathes of voters on our progressive flank then we’re doomed. We need to start listening to them.”
A new technique, which builds on MRP modelling and correctly predicted the Gorton and Denton byelection result, forecasts that Labour, which holds 21 boroughs in London, could lose flagship authorities such as Hackney and Lambeth to the Greens.
The modelling, from the data firm Bombe, will spook Labour MPs, who hold 59 of London’s 75 parliamentary seats, and include Keir Starmer, David Lammy, Steve Reed, Heidi Alexander and Wes Streeting.
According to the forecast, the party would lose more than half its council seats – many to the Greens – in the prime minister’s own back yard, Camden, which would fall to no overall control.
Senior party figures in the capital have warned Labour bosses to urgently address the threat of the Greens. Sadiq Khan, the London mayor, said last week that Labour faced an “existential threat” in parts of the country in May.
“Without a change in course, we risk a repeat of losing large Labour strongholds, like London, just as we did in the 2000s in Scotland. If we don’t unite progressives, we risk opening the door to the darkness and division of Reform,” he said.
Tony Travers, a professor of local government at the London School of Economics, told the Guardian that Labour was on course for a “political earthquake” in the local elections in London if Bombe’s modelling reflected the actual result in May.
“It would profoundly shock London Labour MPs. The national party has taken London for granted for years and invested all their efforts on targeting Reform-prone areas, and they now have this huge flank exposed on their left.”
The gradient-boosted regression modelling (GBRM) uses actual election results in the capital along with polling data from Deltapoll. The AI platform then predicts future voting behaviour over five years.
Labour could be left with an outright majority in just Newham and Redbridge councils, if forecasts are correct. The Greens, if they were to run candidates in every ward, could also take Lewisham, Waltham Forest and Greenwich, as well as Wandsworth, Hammersmith & Fulham, Hounslow and Brent.
The Tories would go up from five councils to six, gaining Barnet, and Reform would take one: Barking and Dagenham. However, Nigel Farage’s party would win 132 seats across London and be the largest party in Havering.
Labour could lose more than half of its council seats across the capital – 741 – according to the model. The Greens would pick up 530, the Tories 77 and the Liberal Democrats 72, as Labour is squeezed on four fronts. The party could also face challenges from pro-Gaza independents.
Nine other boroughs would go to no overall control, with the Greens the largest party in four, Labour in two and one each for Reform and the Tories. The Lib Dems and Labour would have the same number of seats in Southwark, while the Tories and Greens would in Westminster.
A Labour source said: “A slow handclap for those self-appointed strategic geniuses who ridicule Labour values and think we can afford to sacrifice our core vote by mimicking the performative cruelty of Suella Braverman.
“The dead end of McSweeneyism must be abandoned before it’s too late. When Labour focuses on the cost of living we can start to win back the progressive defectors we’ve lost and unite the coalition we need.”
The Greens, however, face a big challenge in selecting enough candidates to fight in every council seat across the capital, which they would need to do to achieve the modelled results.
Mike Joslin, the chief executive of Bombe, which is non-political, said: “Labour is facing wipeout in London in the face of a Green tidal wave. The data shows that Labour’s core voters think Keir Starmer disagrees with them on Gaza, social equality issues and Brexit. They want someone that shares their values.
“Alongside the Green wave, inner-city working-class voters are angry with Labour for not making them better off, and you will see some wards going Reform. Many places are now five-way marginals.”
Joslin, who has in the past provided data for a wide range of Labour figures including Starmer, Angela Rayner, Ed Miliband and Khan, added: “The Greens, if they can get the candidates, could capitalise and win a number of London councils. This could change the landscape of London government for a generation.”
One London Labour MP told the Guardian: “We can’t dismiss voters’ concerns and need to work hard to rebuild trust. We have some incredible Labour councils and councillors doing amazing work in their communities.
“That work risks being undone if Labour nationally doesn’t start addressing worries of progressive voters around policies like welfare cuts, the language government uses on immigration and the response to Gaza.”
A second accused party chiefs of refusing to listen to warnings over the Greens and approaching the threat on their progressive flank like “student politics”. “The chaos that will come from London descending into Green madness with no housing being built and no investment in social care will be catastrophic for the poorest people.”
