Angela Rayner warned Labour faced its “last chance” after the party was hammered in local elections across England, Wales and Scotland this week, and she backed Andy Burnham to return to Westminster as the party searched for a way out of its slump.

The deputy prime minister said it was a mistake to block Burnham from standing at February’s by-election in Gorton and Denton, and urged Sir Keir Starmer to “meet the moment” with bolder action that would make people feel better off. In a 1,000-word statement, she said Labour should give regional mayors more economic powers, raise the minimum wage and promote new forms of public, community and cooperative ownership.

Rayner’s intervention came after Labour lost almost 1,500 councillors in local elections across England, was kicked out of power in Wales and returned just 17 of the 129 seats in the Scottish Parliament. She said the scale of the defeat showed the party was “in danger of becoming a party of the well-off, not working people,” and that it needed to change course quickly.

Starmer will try to shore up his premiership in a speech on Monday, but the pressure on him is not coming only from outside his inner circle. Catherine West, a backbench MP and former junior minister, said she would seek to trigger a leadership contest against him if she was still dissatisfied after his reset speech. That puts the party’s internal discipline on public display just as it is trying to recover from a bruising week at the ballot box.

Rayner’s remarks also underline how quickly the Labour leadership question has returned to the surface. She is seen as a potential contender to replace Starmer, and alongside Wes Streeting she and Burnham are widely viewed as the main possible challengers. Her decision to speak out, and to do so with such bluntness, suggested the argument inside Labour is no longer only about strategy after a bad set of results but about whether the party still knows who it is for.

The losses were driven in part by the surge for Nigel Farage’s Reform UK, while the Greens also cut into Labour support in London and other urban areas. Rayner said Labour should learn from what has worked locally rather than falling back on “an agenda and politics that has failed people,” arguing that the party must bring its best players into Parliament and build a programme that feels rooted in everyday life. Her warning was simple: if Labour does not move now, the next test may not be another setback. It may be the point at which the party stops being trusted by the voters it was built to represent.