Labour leader Sir Keir Starmer will be “dumped into the dustbin of history” if he continues to attack the left of his party.

The stark warning came from Unite trade union boss Len McCluskey.

He said Sir Keir was backtracking on the position he took to replace Jeremy Corbyn as leader.

Mr McCluskey told Times Radio that Sir Keir needed to “shake off the siren voices of New Labour if the party was to stand a change of regaining power”.

He added: “There is a real fear at the moment that he is attempting to marginalise the left.

“Now we seem to be travelling in a direction that is turning the Labour Party into a party of the establishment.

“That will not get you into No 10.

“Keir needs to start telling people what he is and what Labour are.

“People don’t know at the moment.

“People knew where Jeremy Corbyn was coming from long before any elections.

“People knew where Tony Blair was coming from long before any elections.

“At the moment we are suffering because people don’t understand what Keir Starmer stands for or what Labour stands for.

“And that’s what he has to do.

“Stick to the radical nature of the policies he stood on and win back the red wall seats.

“If he continues to attack the democracy in the left of the party, he’ll destroy the unity of the party and the reality will be he’ll be dumped into the dustbin of history.”