Three in five people already expect Labour to lose the next general election, according to a poll.

Sixty per cent of voters believe Sir Keir Starmer’s party will not manage a second term in power, less than three months after its landslide election victory.

The poll, by the More in Common think tank, also found more than half of respondents did not believe Sir Keir would lead Labour into the next election.

Forty-eight per cent of those surveyed said they believed he would still be Prime Minister by the next election, with 52 per cent saying they did not.

Labour has endured a difficult start in government amid a row over Lord Alli, the Labour peer and millionaire donor, donating thousands of pounds towards clothes for Sir Keir.

It emerged earlier this month that the Prime Minister broke parliamentary rules by initially failing to declare more than £5,000 towards clothing that the peer had given to Lady Starmer.

Further damage was done by the revelation that Sue Gray, Sir Keir’s powerful chief of staff, is being paid £3,000 more than him.

He also suffered the biggest rebellion of his premiership a fortnight ago as dozens of Labour MPs refused to support taking winter fuel payments away from 10 million pensioners.

The More in Common research found that almost one in five Labour voters (17 per cent) now regretted their decision to back the party, with Sir Keir’s net approval rating down to -20 points. It had been as high as 11 points in late July after his landslide win.

But his honeymoon period proved short-lived, with the public now more likely to think th at he is doing a “somewhat bad” or “very bad” job.

The think tank said Labour must hit 36 per cent of the popular vote if it is to hold power at the next election, likely to take place in 2029. The party won 33.7 per cent of the vote on July 4, and even a modest Conservative recovery, in which votes were regained from Reform UK, would see the Tories overtake Labour.

The Tories were able to increase their vote share for three elections in a row after their return to power in 2010 before falling to a historic defeat under Rishi Sunak in July.

Luke Tryl, the UK director of More in Common, 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 on to power.”

Mr Tryl said that if Labour was unable to pass the 36 per cent threshold, it could be ousted “even without losing a single vote”.

Meanwhile, Prof Sir John Curtice warned delegates at the Labour conference on Sunday that Sir Keir’s gloomy message about the state of the country could “potentially go down badly”.

Speaking at a fringe event, the election guru said: “A message that says ‘it’s all terrible, and it’s the other lot’s fault’ that isn’t accompanied by an attempt to construct a narrative about the future would potentially go down badly because that’s not what the public wants to hear.”

He also expressed doubt that the Prime Minister “has the ability to construct that narrative” of optimism, adding: “Rishi Sunak couldn’t construct the narrative. I certainly don’t think that Sir Keir constructed the narrative during the election.

“The question is, does he have the political ability to do so? That is still an open question, but constructing that story is important.”

Prof Sir John also said Labour had made a mistake putting a focus on “trust and integrity” and warned that the party could “sow what you reap”. He added:  “Some of the mistakes of this Government are just to do with straightforward political antennae. It’s just spotting the bear traps quickly enough, and the Government does seem to be very slow.

“I think politicians have also made a major mistake about focusing on personal mistakes and foibles and all the rest of it. The truth is, what you sow you reap, and I think you must expect, given the way that you very heavily attacked the integrity of the last Conservative government, that the Conservative Party is going to return it in spades.”