The London Mayor said Labour supporters would be “delusional” if they did not recognise the difficulties the party had had since winning power in July 2024.

After taking Labour into power at Downing Street for the first time since 2010, Prime Minister Sir Keir Starmer has seen his party’s popularity slump in the polls, amid criticism over issues such as welfare reforms.

“It’s been a tough first year,” Sir Sadiq conceded.

Speaking at the Edinburgh Festival Fringe, he insisted that Labour supporters “need to have the humility to recognise” that “otherwise we are being delusional”.

The London Mayor, who was one of the most powerful Labour politicians until Sir Keir became Prime Minister, added: “Those people that say it has been a great first year… I think they are letting the party down.

“It hasn’t been a great first year. There have been great things that have happened in this first year, around the rights for renters, around the rights for workers, around energy security, and I could go on.

“But as first years go, it has not been a great first year.”

However, he said the “good news” is his party has “got another four years to make sure we turn this around”.

The London Mayor – who is a Liverpool FC supporter – said if Labour was in a football match, they would be “two-nil down”

But continuing his analogy, he said that only 15 or 20 minutes of the match had gone, with minutes still to play and to “win this game”.

He said: “It is really important now we really pick things up because I think we are two-nil down.

“But the great news is we have turned it round before, we have won games before where we’re two nil down, we can do it again.”

His comments came as he said that many people who backed the party last year had “lent us their vote”.

Sir Sadiq said: “They didn’t sprint toward Labour at the ballot box, they lent us their vote, gave us the benefit of the doubt.”

After over a decade out of power at Westminster, he also said that the party had “lost the memory of running things”.

Sir Sadiq said: “It has taken some time for the Labour Party, the Labour Government, to understand how the machinery of government works.”

But he added: “There are some really, really good people in the cabinet, there is a good back office team as well. So I have got confidence we will turn it round.”

He added: “With Keir and the team we’ve got in Number 10, and across Whitehall, Westminster, we’ve got a great team.

“They are not performing to the level I know they can perform at. I’m not being critical of them, I think they themselves would admit they can do much more.

“So I am hoping the next three, four years you will really see the best of this government.”