Sir Keir Starmer has congratulated Andy Burnham on last night’s by-election victory – just as Mr Burnham prepares his bid to take the Prime Minister’s job.

Sir Keir is bracing for a Labour leadership battle already described as “utter chaos” after Mr Burnham romped to victory in the North West.

The new MP needs the support of 81 Labour colleagues to trigger a leadership contest, and last night insiders revealed he does indeed have those numbers.

The new Makerfield MP intends to present the list of his MPs to Sir Keir to pressure him to step down without a race – what some have termed a “coronation” – according to the New Statesman.

“This is a final chance to change,” Mr Burnham said in his victory speech. “There will be no second chance.”

Earlier, his main allies including Louise Haigh, the former minister, had ordered Sir Keir Starmer to make way and let a peaceful transition of power take place.

While Culture Secretary Lisa Nandy said she imagined the Prime Minister would reach out to Mr Burnham by the early morning for a conversation if he won the seat.

Former Health Secretary Wes Streeting has declared that if Mr Burnham stands in an upcoming race, he will too.

But the beleaguered Prime Minister continues to insist he will not walk away, while loyalists like Home Office Minister Mike Tapp have warned that “all the public will see is utter chaos” if a contest begins.

Mr Tapp added that if Mr Burnham’s agenda was too different from Sir Keir’s, he would also need to call a General Election.