Boris Johnson will today present the UK's final Brexit offer to the EU - and vow to leave with no deal if it is not accepted.
In a blunt message to be delivered in his closing speech to the Conservative Party conference, the Prime Minister out precisely how the government intends to replace the backstop plan to maintain an open border on the island of Ireland.
Johnson said his plan represents a "fair and reasonable compromise" which he hopes Brussels will agree to.
But Downing Street officials insisted that if the EU refuses, the UK will leave the bloc on 31 October without a deal – despite MPs passing a law forcing the PM to seek a three-month extension that the deadline.
Addressing the conference in Manchester, the prime minister said: “Voters are desperate for us to focus on their other priorities – what people want, what Leavers want, what Remainers want, what the whole world wants – is to move on.
“That is why we are coming out of the EU on 31 October. Let’s get Brexit done -- we can, we must and we will.”
Johnson said Labour leader Jeremy Corbyn's plan to delay Brexit would lead to the "chaos and cacophony of two more referendums” in 2020 - one on the EU and another on Scottish independence.
He added: "Can you imagine another three years of this? That is the Corbyn agenda – stay in the EU beyond 31 October, paying a billion pounds a month for the privilege, followed by years of uncertainty for business and everyone else.
“My friends, I am afraid that after three and a half years people are beginning to feel that they are being taken for fools. They are beginning to suspect that there are forces in this country that simply don’t want Brexit delivered at all. And if they turn out to be right in that suspicion then I believe there will be grave consequences for trust in democracy.
"Let’s get Brexit done on 31 October so in 2020 our country can move on.”
A senior Number 10 official said: “The government is either going to be negotiating a new deal or working on no deal — nobody will work on delay.
“We will keep fighting to respect the biggest democratic vote in British history. The EU is obliged by EU law only to negotiate with member state governments, they cannot negotiate with Parliament, and this government will not negotiate delay.”
This is despite an act of parliament initially put forward by Labour MP Hilary Benn which requires him to seek an extension if he cannot strike an agreement.
Downing Street has denied reports that the UK proposals will include a plan for customs checks on either side of the Irish border, up to 10 miles away from the existing frontier between Northern Ireland and the Republic.