The Queen's Platinum Jubilee saw millions of Brits grasp the chance to bask in the sunshine and toast the long reign of their beloved Monarch.
But for Boris Johnson, the bank holiday was a festival of humiliation as the PM - once the 'Heineken Tory' able to win with Red Wall Brexiteers and liberal Londoners alike - faced cold public anger, national ridicule and a plot to oust him from power.
The first signs that Partygate would rain on his parade came as he and wife Carrie pulled up at St Paul's Cathedral for the Queen's thanksgiving service, waving at the crowds who greeted him with a chorus of boos.
His nightmare continued at the Jubilee concert outside Buckingham Palace when comedian Lee Mack openly mocked him from the stage.
“We are here right outside the gates of Buckingham Palace for the party of a lifetime,” he said, adding: “I’ll tell you what – finally we can say the words ‘party’ and ‘gate’ and it’s a positive.”
QI host Stephen Fry was even less sparing of the PM's dignity.
"How many local sewage works has our Majesty opened with a bright smile? How many plaques unveiled?" he asked, marvelling at the Queen's 70-year reign, before pointedly concluding: "How many prime ministers tolerated – for that alone, no admiration is high enough."
If Mr Johnson cut a lonely figure in the crowd, Tory MPs who fanned out into their constituencies for various street parties and community centre dos, weren't seeing the funny side either.
They were confronted - for the first time since Whitehall enforcer Sue Gray published her damning report - by scores of angry voters who obeyed the Covid rules Mr Johnson and No10 staff so brazenly ignored.
When Sunday arrived, broadcasters remarked on an unusually downcast Prime Minister, as, from VIP seats at at Buckingham Palace, just yards from Labour leader Keir Starmer and the royal family, he was watched the pomp and ceremony of the Jubilee parade
It became clear why he appeared so glum.
Sir Graham Brady, the chairman of the 1922 Committee of backbench Tories, had called minutes before the pageantry began to tell the PM he was now losing the support of his Tory colleagues too, and a confidence vote was to follow.
It's understood the PM knew during the pageant that a no confidence vote in him would be called. But extraordinarily he kept the news to himself until afterwards, digesting it while he cut a lonely figure in the crowd.
He took the call just as he was heading off to the pageant - and did not even tell his closest aides, only getting round to doing so after he got back.
A senior Conservative Party source said: "It turns out that he actually took the call just as he was heading off to the pageant, so didn't have time to sort of communicated even to his closest advisors till after the pageant was done.
"So he sat there, you know, smiling at the performances for a couple of hours wondering what to do, and then rang a few of us to get around last night and get on with it."
It bookended a miserable Jubilee weekend for the beleaguered PM, who spent Sunday night at No10 plotting how to bounce back his team of closest allies, which included chief of staff Steve Barclay, chief whip Chris Heaton-Harris, communications director Guto Harri and the elections mastermind Sir Lynton Crosby.
The political survival of Mr Johnson may no longer be in their hands.
