Labour’s biggest union backer has issued a dire warning to the party that they must “change or die” as the future of Sir Keir Starmer’s time in Downing Street hangs in the balance.

Unite general secretary Sharon Graham has said the “writing’s on the wall”, adding that Labour has “abandoned” the working class.

She said: “[The working class] have delivered their verdict. They have painted the ballot boxes of our towns and swathes of the Midlands and the North turquoise and even green. They have done so using the brush of decades of Labour failure.

“Labour ministers can loyally read out lists of their achievements, but no one is listening. If every one of those achievements were in stereo, they wouldn’t even touch the sides of the vision that is needed now.

“We are stuck in a rigged system where everyday people always, always pay.

“Only fundamental, irreversible change will stem the tide. If the party does not shift decisively towards the working class it is finished. It is change or die. Now or never.”

Reform UK piled on councillors across the country as party leader Nigel Farage claimed there had been a “truly historic shift in British politics”.

Labour also suffered from voters switching to the Green Party as Zack Polanski declared the era of two-party politics “is not just dying, it is dead and it is buried”.