Jamie Oliver has threatened to stage an "Eton Mess" protest over the government's U-turn on its anti-obesity strategy.
The celebrity chef has told the Prime Minister that he has "36 hours" to correct his mistake and called on the public to gather outside Downing Street on Friday at 12.30pm with bowls of dessert "invented in that very privileged place" where Boris Johnson went to school.
The government has decided to delay a ban on two-for-one deals on unhealthy food, a move that has come under fire from campaigners including Oliver, who has called it a "wasted opportunity" that erodes the UK's efforts to tackle obesity.
He added that a ban on junk food adverts on TV before the watershed was key to protecting children.
The ban has been put on hold for a year.
"I would love to give you the opportunity if possible to realise that it's OK to make a mistake," he said in a video posted on Instagram.
"What I'd like to say to you is you've got 36 hours to go back on your U-turn on your own law that your government put in place.
"We are not the enemy. It's actually your own people internally who are trying to get your job and backstab and stir."
He added the demonstration would be about "positivity" and aims to encourage the government to "do the right thing".
Ministers decided to defer the ban on buy-one-get-one-free deals on foods with a high level of fat, sugar and salt in England for 12 months, to enable them to review the impact on budgets in the face of the cost-of-living crisis.
The move has been welcomed by the industry and some Conservative MPs who opposed it.
Former Tory leader William Hague has branded the weakening of anti-obesity strategy "morally reprehensible".
"While some measures, such as rules on the positioning of unhealthy foods by retailers, will still go ahead in October, this U-turn adds to the long history of failed obesity strategies," he said in The Times on Tuesday.
Former Health Minister Lord Bethell also criticised the move, saying that failing to tackle obesity would add to the costs of the NHS.