Burnham's stuttering BBC2 performance was further ammunition for Starmer's most die-hard supporters. Led by the Prime Minister's wife, they believe he should fight the 'lightweight' Burnham.

Labour MPs backing the Prime Minister said he 'is not going anywhere' amid a push to prevent a coronation for Mr Burnham as Sir Keir's replacement.

Cabinet ministers are bracing for a challenge to Sir Keir Starmer's leadership as early as the end of June if Andy Burnham succeeds in the Makerfield by-election