Rayner: Starmer needs to ‘set out change’ and bring back Burnham

She added that it had been a mistake to block Andy Burnham’s possible return to Westminster, saying Labour needs to bring its “best players into Parliament”.

Greater Manchester mayor Mr Burnham is also seen as a potential rival to Sir Keir, but his attempt to stand in the Gorton and Denton by-election was thwarted by Labour’s hierarchy.

In a 1,000-word assessment of what Labour needs to do, Ms Rayner said: “What we are doing isn’t working, and it needs to change. This may be our last chance.”

In England, Nigel Farage’s Reform UK snatched councils, some of which had been Labour for generations, in northern England while Zack Polanski’s Green Party lured voters away in former urban strongholds, including taking control of some London authorities.

In Wales, Labour was reduced from the party in government to a single-figure rump in one of its former heartlands.

Ms Rayner said: “In London, we lost young people who fear they will never afford a home. In my patch and across the north, we lost working people whose wages are too low and costs too high. In Scotland and Wales, people do not currently see Labour as the answer.

“We are in danger of becoming a party of the well-off, not working people.”

Sir Keir will deliver a speech on Monday at the start of a potentially make-or-break week for his premiership.

On Wednesday the King’s Speech will set out his Government’s priorities in Parliament.

Ms Rayner said: “Policy tweaks will not fix the fundamental challenges facing our country. This Government needs, at pace, to put measures in place that make people’s lives tangibly better, while fixing the foundations of a system rigged against them.

“The Prime Minister must now meet the moment and set out the change our country needs.

“Change our economic agenda to prioritise making people better off, change how we run our party so that all voices are listened to, and change how we do politics.

“Labour exists to make working people better off. That is not happening fast enough, and it needs to change – now.”

Ms Rayner quit as deputy leader and deputy prime minister last September after failing to pay the correct tax on a flat in Hove.

In her statement on Sunday she was critical of some decisions made while she was in the Government: “The Peter Mandelson scandal showed a toxic culture of cronyism.

“Decisions like cutting winter fuel allowance just weren’t what people expected from a Labour government.”

Ms Rayner’s intervention came as Labour MP Catherine West threatened to launch a leadership bid unless Sir Keir’s speech on Monday can persuade her he understands the scale of the challenge facing the party.

The former minister has made clear her campaign is an attempt to force the Cabinet to get behind a candidate to move against Sir Keir rather than a credible challenge to win the keys to No 10 herself.

She told BBC’s Sunday With Laura Kuenssberg: “I will hear what the Prime Minister’s got to say tomorrow and, then if I’m still dissatisfied, I will put out my email to the Parliamentary Labour Party, asking for names.

“And the reason I’m doing that is not for me.

“It’s for working people, because Labour is the only party that can beat Reform.”

Her move has angered the party’s left, who fear a “palace coup” to install one of the Cabinet without a vote.

A contest triggered quickly would also prevent Mr Burnham from standing as he is not an MP.

Richard Burgon, secretary of the Socialist Campaign Group of MPs on the left, warned Ms West against supporting a “Cabinet stitch-up” to replace Sir Keir.

“I fear there’s a real danger that, whatever her good intentions, her move will be exploited by people on the right of the party who want a coronation and not a proper democratic contest in the party,” he said.

In the latest sign that discontent with the Prime Minister has gone beyond the usual critics on the Labour left, former minister Josh Simons called for him to go.

The Makerfield MP wrote in The Times: “Putting the people I represent and the country I love first, I do not believe the Prime Minister can rise to this moment.

“He has lost the country.”

Education Secretary Bridget Phillipson acknowledged people felt “bitterly let down” by Labour.

But she said: “I just do not believe that the message we should take from these elections is that we ought to spend time as a party amongst ourselves, arguing amongst ourselves, fighting amongst ourselves.”

She said Sir Keir “will set out a fresh direction for our country and for our party that will rise to the scale of what we face”.