Boris Johnson took a hammer to Theresa May's Brexit plan today as he claimed her proposals were "dangerous and unstable".
Addressing a packed fringed meeting at the Conservative party conference, the former foreign secretary dubbed the so-called Chequers plan "an outrage" that was "not democracy".
With a host of Tory MPs watching on, including former Brexit secretary David Davis and ex-party leader Iain Duncan Smith, Johnson even suggested May and other Cabinet ministers could be prosecuted under an ancient law that bans foreign courts from having jurisdiction in the UK.
The biggest cheers from the 1,000-strong audience came when Johnson warned that the UK could not fudge Brexit now and get a better deal later, and when he defiantly called on the government to "chuck Chequers".
While MPs in the hall gave him an ovation, other Tories spoke out against Johnson's speech. Former Defence Minister Guto Bebb said: "More than two years since the referendum, Boris Johnson still has no answers to the difficulty questions posed by Brexit."
Speaking from the stage, Johnson said: "If we get it wrong, if we proceed with this undemocratic solution, if we remain half-in half out, we will protract this toxic tedious business that is frankly so off-putting to sensible middle of the road people who want us to get on with their priorities.
"If we cheat the electorate – and Chequers is a cheat – we will escalate the sense of mistrust."
However, Johnson ended his speech by saying Tory members should back May and convince her to support a looser free trade agreement with the EU along the lines she set out in her Lancaster House speech in January 2017.
Tory members began queueing for Johnson's speech more than 90 minutes before he was due to take to the stage.
Many of those were wearing 'Chuck Chequers' badges to highlight their opposition to May's negotiating strategy, which would see the UK follow the EU rulebook on goods and agri-foods in order to avoid additional customs checks.
Johnson entered the hall to a standing ovation, with his father Stanley and sister Rachel – who opposed Brexit – watching from the front row of the auditorium.
The former London mayor used the opening 20 minutes of his speech to attack Labour leader Jeremy Corbyn, and talk up his own support for UK business.
In June, it was reported that Johnson had said "f**k business" during a meeting in Brussels – a comment which led former CBI chief Lord Digby Jones to brand Johnson "irrelevant and offensive" during a conference speech on Sunday.
Calling on his colleagues to "take this Tony Benn tribute act and wallop it for six", Johnson urged his party not to imitate the opposition.
He said: "We won’t get anywhere by metaphorically acquiring beards and string vests and allotments – but by systematically pointing out the damage they would do.
"They want to spend literally hundreds of billions renationalising the utilities.
"They want to clobber business with new taxes, with workers’ soviets on the board.
"They would wreck the economy. They would drive away investment."
Johnson focused a large part of his speech on the housing crisis, saying that building more homes is "a massive opportunity for us Tories."
He added: "I have lost count of the times – and I bet you have too – when I have been out campaigning, and someone has told me on the doorstep that they would vote Conservative forever out of sheer gratitude to us for letting them buy their own home."