Leaving the EU on the terms of the Chequers plan would be a "mistake" and would be the "perfect" way for the UK to return to the EU, Boris Johnson has said in an eagerly-anticipated speech at the Tory conference in which he told the audience to "chuck Chequers".
The former foreign secretary said currently the UK did not appear to be "taking back control" but was instead "forfeiting control" to Brussels, which was a "constitutional outrage" and that if the Chequers plan was agreed on, the UK would be "paraded in manacles" in front of the EU.
He added that the Prime Minister's Brexit blueprint showed that the "UK was unable, ultimately to take back control", and we would be "humiliated" if we left the EU on its terms and ended up "half-in, half-out".
Mr Johnson - who quit Mrs May's Cabinet in protest over her Chequers plan - told the hall that it was "sad" and "desperately wrong that we are preparing to agree terms with Brussels that would make it difficult if not impossible" to do "proper free trade deals" with the rest of the world if the Chequers plan was agreed to.
He continued: "We will not only be prevented from offering our tariff schedules, we will be unable to make our own laws, to vary our regulatory framework for goods, agrifoods and much much more besides.
"This is politically humiliating for a £2 trillion economy."
Watch Boris Johnson's speech in full
He also warned that "if we cheat the electorate - and Chequers is a cheat - we will escalate the sense of mistrust.
"We will give credence to those who cry betrayal, and I am afraid we will make it more likely that the ultimate beneficiary of Chequers will be the far right in the form of Ukip, possibly others, and therefore the far left in the form of Jeremy Corbyn."
His call to "chuck Chequers" and "truly take back control" was met with rapturous applause and cries of "chuck Chequers" returned.
Ending his speech, the 54-year-old urged Tory delegates to persuade and "back" Mrs May to the hard Brexit blueprint she first set out in her Lancaster House speech, when she said she would take the UK out of the customs union, single market and jurisdiction of the European Court of Justice.
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Mr Johnson said it was this, not the Chequers plan which needed backing "because if we get it wrong we will be punished. And if we get it right we can have a glorious future.
"This Government will then be remembered for having done something brave and right and remarkable and in accordance with the wishes of the people."
He won a standing ovation from audience members at the end of his speech.
ITV News Political Editor Robert Peston said Mr Johnson's speech marked the first time at the conference that both the Prime Minister's Chequers plan and her authority had been "seriously challenged"
The speech was widely seen to be Mr Johnson's pitch to replace Theresa May as leader, and the former mayor of London received a standing ovation as he took to the stage.
One of the first things Mr Johnson said in his speech was that he wanted to "put some lead in the collective pencil" and stop the "relentless seeping away" of Britain’s self-confidence as the Brexit date draws closer.
He added that "there is only one thing I really worry about in this critical autumn of 2018, and that is that, after 200 years, this oldest and most successful of all political parties should somehow lose confidence in its basic belief in freedom...
"And that we should be so demoralised and so exhausted as to submit those institutions - forever - to foreign rule."
However, Mr Johnson kicked off his speech on a lighter note joking that the only Treasury forecast he has agreed with in ages, was Philip Hammond's prediction in the Daily Mail that he would never become Prime Minister.
The former mayor of London also called on on Tories to stick to their tax-cutting guns, which will come as a rebuke to Chancellor Philip Hammond, who has openly admitted taxes will rise to help pay for the £20 billion spending boost promised to the NHS.
In what could be seen as a swipe at Mrs May’s focus on righting “burning injustices” in society, Mr Johnson also urged the party not to “ape Corbyn” but to “take basic conservative ideas and fit them to the problems of today”.
“We must on no account follow Corbyn, and start to treat capitalism as a kind of boo word," the Uxbridge and South Ruislip MP said.
Mr Johnson said Tories should have as their objective to "cut taxes for those on low and modest incomes - because it is Conservative to give people back control of their money", and that lower taxed would "stimulate investment and growth".
"And instead of treating business as if it were somehow morally dubious, we Conservatives should celebrate its power to do good, and the success of British business today."
He also warned against losing faith in "competition and choice and markets".
"Indeed we should restate the truth that there is simply no other system that is so miraculously successful in satisfying human wants and needs."
The talk was well attended, with hundreds of delegates queuing up more than an hour before the speech began.
In another rebuke of one of Mrs May's policies, Mr Johnson won loud applause when he called for the return of stop and search - something the Prime Minister has curbed.
Another way in which Mr Johnson called for the party to follow its Conservative instincts, was by giving millions more young people the chance to become owner-occupiers.
He called for a crackdown on landbanking (holding pieces of land for future sale) and encouragement for small private builders.
Mr Johnson said the big eight house-builders were abusing their dominant position.
He said councils should be given the ability to retain stamp duty, council tax, and business rates, which would act as a motive for growth.
Speaking at the meeting hosted by the ConservativeHome website, Mr Johnson also used his speech to launch an attack on Jeremy Corbyn's Labour, saying: "Surely to goodness we can take on this Tony Benn tribute act and wallop them for six.
"Not by imitating them, not by capering insincerely on Labour turf ... but by systematically pointing out the damage they would do."
Attacking last week, Mr Johnson said: “It was astonishing that he had absolutely nothing to say about the wealth-creating sector of the economy – the people who get up at the crack of dawn to prepare their shops, the grafters and the grifters, the innovators, the entrepreneurs – he didn’t mention any successes.
“We Conservatives know that it is only a strong private sector economy that can pay for superb public services and that is the central symmetry of our one nation Toryism.”
Mr Johnson's speech was part of a flying one-day visit to a conference which has witnessed open warfare within the Tory party over Brexit, which critics say he has done nothing to calm.
And he pointedly contrasted his record as the figurehead of the Leave campaign with that of the Remain-backing Mrs May, saying: “Unlike the Prime Minister, I fought for this.”