Len McCluskey has suggested trade unions will reconsider their support for Labour if Jeremy Corbyn launches a new political party. The former leader of Unite, who is a staunch supporter of Mr Corbyn, said thousands of union activists want an alternative to Prime Minister Sir Keir Starmer’s party.

Labour is wrangling with growing disaffection with Sir Keir’s leadership and the direction of his government. The PM’s flagship welfare reforms were gutted in a backbench rebellion, Sir Keir was forced into a U-turn on starting a grooming gangs enquiry and rowed back on axing Winter Fuel Allowance payments. He now faces another revolt among his own MPs over special needs provision in schools.

Divisions have also been exposed by the Government’s refusal to scrap the two-child benefit cap, which has angered left-wing Labour MPs. Last week, former Labour MP Zarah Sultana said she was to “co-lead the founding” of a new outfit with Mr Corbyn.

Mr McCluskey told GB News that if the new party proves to be credible, then he would join it, campaign for it and urge trade unions to back it.

He said: “Many thousands of union activists are demanding a credible and radical alternative to Labour.” The former union leader warned without an alternative, there is a risk voters will turn to Nigel Farage’s outfit.

Mr McCluskey warned: “As ordinary people get disillusioned, they will turn to Reform UK, which is why there is a desperate need for another choice.”

To date, Mr Corbyn hasn’t said much about a new party. When Ms Sultana announced she was leaving Labour, the former party leader congratulated the Coventry South MP on her “principled decision” and said the “democratic foundations of a new kind of political party will soon take shape”.

He said: “Together, we can create something that is desperately missing from our broken political system: hope.”

Mr Corbyn’s former director of communications, James Schneider, welcomed Mr McCluskey’s support for a new party, describing his remarks as “encouraging”.

Mr Schneider told GB News: “We have had a year of the new Labour Government that promised change and has not delivered it. There are millions of people across the country who are simply not represented in the political system.”

Having led Labour from 2015 to April 2020, Mr Corbyn stepped down from the top job after the party’s loss at the 2019 general election. He was suspended from Labour in 2020 after he refused to fully accept the Equality and Human Rights Commission’s findings that the party broke equality law when he was in charge, and said antisemitism had been “dramatically overstated for political reasons”.

The MP for Islington North was blocked from standing for Labour at last year’s general election and expelled in the spring of 2024 after announcing he would stand as an independent candidate in the constituency, which he won with a majority of more than 7,000.

Last year, Mr Corbyn formed the Independent Alliance with other Independent members of the Commons.