Bin workers walked out indefinitely on March 11 over cuts by Birmingham council that Unite claims will cause 50 workers to lose £8,000 a year and 20 more to lose about £2,000.

The strikes have prompted fears of a public health crisis and seen rubbish piling up in the streets. The council insists Unite’s figures are wrong and has repeatedly called on the union to end the walkouts.

Asked how he would handle the situation, Mr Corbyn said: “We would look obviously at the situation of Birmingham city [council] finances but insist that no worker’s wages go down and you restructure the finances accordingly.”

The upstart party is likely to further harm Labour in a similar way to how the rise of Reform UK has hurt the Tories on the Right.

But Cabinet minister dismissed Mr Corbyn as “chaotic” and mocked the new party.

Asked about the launch, Peter Kyle, the Science Secretary, told Times Radio: “I was a Member of Parliament in the Labour Party when Jeremy Corbyn was leader and the chaos and instability that he brought to our party, I’m now viewing him wreak in his new party.

“And I’m just very glad that I’m looking on it from the outside this time, rather than having to experience it from the inside.”

Mr Corbyn led Labour to two general election defeats in 2017 and 2019, with the latter being the party’s worst performance at the ballot box since 1935.

He survived a leadership challenge in 2016 after more than 170 of his own MPs passed a non-binding motion of no confidence in his leadership.

However, polling suggests a party led by Mr Corbyn could pick up about 10 per cent of the vote at a general election, splitting the Left and making it significantly harder for Labour to defend its majority.