RMT general secretary Mick Lynch has accused Labour of conducting a “purge” of the left and said that he does not have confidence in Sir Keir Starmer.

The rail union leader urged Sir Keir to include left-wing policies in the party’s election manifesto following controversy over its candidate selection processes.

Mr Lynch’s criticism came after former shadow chancellor John McDonnell warned that the Labour leadership is allowing a “right-wing faction” to become “drunk with power” and attempt to “destroy” the left of the party.

The RMT leader told ITV’s Peston programme on Wednesday night that he agreed with the comments by Mr McDonnell, who was shadow chancellor under Jeremy Corbyn.

Mr Lynch said: “The left is being purged and we need a balance.

“We’ve got people in the centre, people in the traditional right have got their place and the people on the left should be able to put their ideas forward.”

Pressed on whether he backed Sir Keir, Mr Lynch replied: “I don’t have confidence in him.” 

He added that RMT, which is not affiliated to Labour, would “prod and pressure” Sir Keir to deliver for working people, “rather than delivering the agenda of the Daily Mail or the Telegraph or being a bland version of the Tory Party.”

Mr Lynch added: “Keir Starmer needs to be putting some of those ideas forward in terms of housing, funding our NHS and turning this country around so that people can believe in him, rather than triangulate around what he thinks middle England thinks.

“He needs to deliver for working people — that’s his job and he needs to show that he is going to get on with it.”

Mr Lynch was one of a number of trade union leaders who wrote to Labour last month accusing the party of scoring a “monumental own goal” by blocking a left-wing Labour mayor from running for mayor of an enlarged region replacing his existing one.

North of Tyne Mayor Jamie Driscoll, who has been described as the “last Corbynista in power,” has been barred from the long list of possible candidates to run the expanded North East Mayoral Combined Authority.

Mr Corbyn has been blocked from standing for Labour in Islington North, the constituency he has held for 40 years, by an unprecedented NEC motion accusing him of being a drag on the party’s vote. His most recent majority was 26,188.