The majority of the public already expect Labour to lose the next election, new polling shows.

The survey found 60% believe Sir Keir Starmer’s party will be ousted in 2029, while half think he will not still be Prime Minister then.

Analysis by the More in Common think tank also found Labour could be defeated without losing a single vote if the Tories rally former voters who stayed at home and take half of those who switched to Reform.

Sir Keir’s party needs to increase its vote share from 33.7% at the 2024 election to at least 36% in 2029 to see off such a threat.

More in Common’s UK director Luke Tryl said: “It may seem extremely premature to be looking ahead to the next election just months after the last one, but with such a volatile electorate Labour needs to be thinking not just about how to hold on to its existing coalition, but how to grow that broad but shallow base of support if it is going to have any chance of holding onto power.

“Our analysis suggests a modest growth in their vote share to 36% is the magic number that would allow the party to see off a threat from a ‘united right’.

“Fail to do that and the party could find itself out of office, even without losing a single vote.

“Growing Labour’s base will require Keir Starmer to appeal to the left and right – winning over those moderate Conservatives who almost made the leap to Labour this time, while also winning back jaded progressive voters who don’t yet think Labour is being bold enough.”

If the Tories were able to mobilise ex-voters who did not turn out in July and half of those who backed Nigel Farage’s party they would win 293 seats to Labour’s 273.

But if Labour increased its vote share to 36% it would have a working majority of 50 even if the Conservatives pulled back former voters and Reform supporters.

More in Common polled 2,005 British adults between September 16 and 18.