Keir Starmer is facing his Waterloo after Andy Burnham was given the green light to fight a by-election on the anniversary of the famous battle.
Labour's National Executive Committee yesterday waved through permission for the Mayor of Greater Manchester to stand for the Makerfield seat after an ally stood down.
If chosen by the local members, which seems a formality, Mr Burnham will be on the ballot on Thursday, June 18 – celebrated every year by the Army to mark its greatest victory – the crushing defeat of Napoleon Bonaparte in 1815.
A Burnham victory will spell the beginning of the end for Sir Keir, allowing his rival back into Westminster from where he will launch a leadership challenge.
The wounded Prime Minister, who has a seat on the NEC officers' committee, was unable to block his rival from standing for a second time, having denied him the opportunity earlier in the year.
Sir Keir is now widely seen as a lame-duck PM, and received little support from his long-time sparring partner, Donald Trump, yesterday.
The US President said it will be 'tough' for Sir Keir to survive the crisis engulfing him as the Government faces months of paralysis.
Keir Starmer (pictured with British soldiers at Salisbury Plain in Wiltshire in 2022) faces the most important battle of his career on Trafalgar Day
Andy Burnham (pictured) was finally given permission to apply to stand for the seat on Friday by the Labour Party's National Executive Committee (NEC)
Mr Trump said: 'It's a tough thing, unless he can straighten out immigration – where he's weak – and if he doesn't start drilling and stop with the windmills all over the place... he's got to open up the North Sea.'
Tory leader Kemi Badenoch warned that Labour infighting would paralyse the Government for months.
The PM's attempts to push through his agenda – notably plans to reform the immigration system and curbing jury trials – now look to be a considerably harder task as MPs could openly rebel with his authority diminished.
A Whitehall source said civil servants would 'down tools' until the uncertainty is settled, while a Labour source described the chaos as a 's*** show at the f*** factory'.
Sir Keir's position weakened further yesterday as first his deputy, Lucy Powell, then his rival, Wes Streeting, backed Mr Burnham's return to the political frontlines.
Mr Streeting, now a backbencher for the first time in six years following his resignation as Health Secretary on Thursday, said: 'We need our best players on the pitch. There is no doubt that Andy Burnham is one of them.
'The Makerfield by-election will be tough. Votes will need to be earned.'
Mr Streeting's support came as allies confirmed he would stand in a leadership election, with him offering an option on the Right of the party and Mr Burnham the Left.
Ms Powell, who was sacked from Cabinet by Sir Keir in a mini-reshuffle last year, warned there must be 'absolutely no attempt' by Downing Street to block Mr Burnham's return.
Wes Streeting, who quit on Thursday and will also stand for the Labour leadership, today demanded Andy Burnham is not blocked from making a return to the Commons
Ms Powell, the only NEC officer to vote in favour of Mr Burnham standing in February's Gorton and Denton ballot, added: 'We've got to do our politics differently. We've got to end the factionalism.'
Those close to Sir Keir suggested it could be Mr Burnham who tastes defeat on Waterloo Day.
A Labour source quipped: 'I wonder if it will result in a plucky revolutionary being sent home with his tail between his legs?'
Reform UK leader Nigel Farage added: 'If Andy Burnham thinks he can use local people to waltz in as leader of this failing Labour Government, we will throw everything we can at this to give him a very nasty shock.
'This by-election will be a modern-day Battle of Waterloo.'
Reform deputy leader Richard Tice said his party will campaign on a platform of 'Make Burnham history'.
Ben Walker, founder of the Britain Elects polling firm, said while Reform stormed to victory at the local elections around Makerfield, Mr Burnham could swing it for Labour.
He added: 'He is gold dust among certain sectors of the electorate. He's the only figure whom Reform voters don't out-and-out hate.
'If he were the Labour candidate, it wouldn't be the Labour Government versus Reform, it would be Burnham's Labour versus Reform – that's the narrative Burnham wants to put out there.'
Labour is already doing everything it can to hold the seat, with MPs travelling up yesterday to begin campaigning.
They also received a boost as it was claimed the Green Party is considering standing a paper candidate and withholding resources from the seat.
A party source revealed it was more focused on saving resources for the Manchester mayoral by-election, in which they believe they stand a much better chance.
Last night, one of Labour's biggest donors promised to bankroll Sir Keir's fight to stay in the job.
Eco-tycoon Dale Vince said: 'I'd help him [Sir Keir].
'If he was saying to me, 'Look, I need a bit of cash,' then I'd be willing.'B
Battle that finally put Napoleon in his place
The Battle of Waterloo marked the end of Napoleon Bonaparte's European ambitions and was one of the biggest strategic mistakes in his military career.
On June 16, 1815, he marched his troops into Belgium and attacked Prussian forces under the command of Gebhard Leberecht von Blucher.
The French defeated the Prussians but were unable to crush their army completely.
Two days later he led his 72,000 troops to a village called Waterloo where the Duke of Wellington's 68,000 troops were camped.
In a critical oversight, Napoleon waited until midday to attack to allow the waterlogged field to dry.
This gave Blucher time to rally the remaining 30,000 Prussian troops, tipping the balance against the French.
Wellington said the battle was 'the nearest-run thing you ever saw in your life'.
The Battle of Waterloo marked the end of Napoleon Bonaparte's European ambitions and was one of the biggest strategic mistakes in his military career