Dozens of Labour MPs have broken ranks to warn that Sir Keir Starmer has to change direction immediately if he wants to save the party. The intervention comes days after dire local election results and highlights the growing tensions within the party just one year after its landslide majority.

The Labour Red Wall Group, formed last year to represent the voices of MPs in left-behind areas in the Midlands and North, turned on Chancellor Rachel Reeves and “Treasury orthodoxy”. In their letter, published openly on Wednesday, the caucus warned their leader that voters have now said “loudly and clearly that we have not met their expectations”. They also warned that Sir Keir’s reaction to his election drubbing “has fallen on deaf ears”.

A total of 45 MPs signed the letter demanding an urgent mission to “rebuild the social contract” – beginning by restoring the winter fuel allowance to millions of pensioners.

Bassetlaw MP and leader of the group Jo White said that responding to voters’ fury “isn’t weak, it takes us to a position of strength”.

Most notably, the letter launches an all-out attack on Ms Reeves, demanding a “breakaway from Treasury orthodoxy, otherwise we will never get the investment we desperately need”.

There are growing calls for the Treasury itself to be split up or abolished, with Labour peer Maurice Glasman saying: “I believe the abolition of the Treasury is necessary for our economic renewal.”

The founder of the socially conservative Blue Labour movement added: “It is an outdated institution at odds with contemporary reality.

“We have reached the end of the road in terms of monetary and fiscal policy and must embrace a different logic of reindustrialisation. The Treasury is ideologically neo-classical in its economic method and hostile to the interests of the country.”

In conclusion, the Red Wall Group letter also demands an improvement to the Government’s communication efforts, with a better attempt at “articulating our values in the language that resonates and is heard”.

It said: “Labour cannot afford to lose the Red Wall again as it reopens the route to a future of opposition and an existential crisis.

“Without Red Wall communities, we are not a Labour Party. The Government has to act now before it’s too late.”

Connor Naismith, who signed the letter, added that the revival must include: “Better public transport in our local area, fewer boarded-up shops, good, secure, well-paid jobs in our towns and a sense that we live in a country which is fair, where everyone is equal under the law.”