In an explosive intervention at the Conservative conference in Birmingham, the former foreign secretary warned that the only winners from a Chequers-style Brexit would be the far-right and far-left in British politics.
Johnson's speech was as much of a threat to Chequers as it was a pitch for the leadership, and saw him making "his most impassioned attack yet on May's handling of Brexit", says the London Evening Standard. "Sadly I think that would reduce the number of cars made in the United Kingdom and that would cost jobs".
"I think it's got to wait until after Brexit", said one, 72-year-old Alan Dixon.
But he added: "I believe that when the Prime Minister lands this deal and brings it back, there will actually be a boost to the economy, as businesses start making those investments that they've deferred over the past year or so, consumers start spending on big-ticket items as they feel more confident knowing where we are going in the future".
The Prime Minister will say that as Britain faces this "moment of opportunity", the Conservatives will always act in the "national interest" and put the needs of hard-working people first.
"That is that Jeremy Corbyn is to wealth creation what Diane Abbott is to mathematics".
Pro-EU Conservatives, who have been sidelined since the country voted in 2016 to leave the EU, think opinion is turning in their favour now that the downsides of Brexit are becoming clearer.
May is ending the party's annual conference Wednesday with a call for the party to show that it "delivers on the issues (voters) care about and is comfortable with modern Britain in all its diversity".
"We are mobilising the people's army of this country that gave us victory in Brexit and will never rest until we have become an independent, self-governing, proud United Kingdom".
Yesterday, Mr Johnson took the conference by storm as he spoke at what was dubbed the "chuck Chequers rally".
But the conference has been dominated by Brexit, with eurosceptic lawmakers attracting hundreds of Conservative members to their events on the fringes.
Mr Johnson said that Mrs May's blueprint - which ties Britain to a common rulebook with the European Union for trade in goods - would be "politically humiliating for a £2 trillion economy" and would prevent the United Kingdom from making its own laws and subject it to the directives of Brussels.
In a rhetorical flourish, he said the Chequers Plan would result in the equivalent of Britain being "paraded in manacles down the Rue de la Loi [in Brussels] like Caractacus". The Brexiteer managed his largest applause when he attacked May's Chequers deal, branding it as "not pragmatic, it is not a compromise".
The Tories should "not fear" a Brexit on World Trade Organisation terms, he said, adding that it could be a "proper, red-blooded, Conservative approach to governing that frees the people from being tied down". That's all right - we'll rebrand it a people's vote. This is an outrage. This is not taking back control: "this is forfeiting control", he said.
Afterwards, the former Cabinet minister won praise from his fellow Brexiteers.
He said: "We must engage in this battle and turn our fire on the enemy, Jeremy Corbyn and his risky hard-left ideas".