Any attempt by MPs to add a customs union to the government's Brexit deal would be "procedural tricks" meant to frustrate departure, a senior minister has said, ahead of yet another potentially momentous day in parliament.
"An agreement has been negotiated".
That defeat leaves Mr Johnson under mounting pressure to find a way out of paralysing impasse on when and how Britain would leave the European Union bloc after Britons narrowly voted to exit in a 2016 referendum.
Johnson sent the letter as required by legislation known as the Benn Act, but did not sign it and also sent a second letter - which he signed - that said a delay would be a mistake.
At a rare Sunday meeting of ambassadors of the 27 states that will make up the EU after Brexit, the diplomats made a decision to forward Johnson's deal to the European Parliament for its required approval.
The amendment - put forward by Oliver Letwin, an independent MP - also forced Britain to ask the European Union to delay Brexit from 31 October to 31 January if the new deal had not yet been approved by the end of this month.
Boris Johnson is making a fresh bid to deliver on his promise to take Britain out of the European Union on October 31 amid mounting optimism that he now has the backing to get his deal through Parliament.
On Sunday Michael Gove, a close adviser to Johnson, told the UK's Sky News: "We are going to leave on October the 31st".More news: Twitter's Android app gets OLED-friendly dark mode in new alpha build
The government is expected to introduce legislation implementing the deal as early as Monday with a vote coming on Tuesday.
Sitting in Parliament on a Saturday for the first time in 37 years, MPs voted to postpone a decision on whether to back a Brexit deal, with the European Union withholding their approval until detailed legislation to implement the agreement has been passed.
"I am afraid I am asking the DUP, just as we are having to choke down extremely hard compromises to get out in the national interest, I think on this issue", he told Today.
Prime Minister Boris Johnson has reaffirmed his commitment to deliver a Brexit deal by the October 31, 2019 deadline. The EU, which has grappled with more than three years of tortuous Brexit crisis, was clearly bewildered by the contradictory signals from London.
On Sunday the opposition Labour party declared that was exactly what happened.
Opposition MPs signalled on Sunday that they won't be backing down either.
An anti-Brexit demonstrator waves a Union flag alongside a European Union flag outside the Houses of Parliament in London.
The government has proposed a debate on the deal, according to the House of Commons order paper which says the speaker will make a statement on the proceedings shortly after parliament opens at 1330 GMT (9.30 pm on Monday, Singapore time).More news: Alexandria Ocasio-Cortez to Endorse Bernie Sanders at NYC Rally
"And we will have to see tactically how we get there".
But he did not sign it and he sent a second letter saying he did not really want the extension.
"People weren't just misled, they were lied to", he said.
"The EU will probably pursue this strategy until there is clarity on the British side", he said, speaking on condition of anonymity.
The first amendment - which passed by 320 votes against 317 in Westminster on Saturday (19 October) - delayed formal approval or rejection of the new Brexit deal until the government has put forward detailed legislation on the new arrangements.
Protesters in an anti-Brexit, "Let Us Be Heard" march on Piccadilly in London, as they head to Parliament Square.
Mr Varadkar said he believes the risk of a no-deal is "relatively low".
During the case's first hearing on October 9, the Government's lawyers assured the court that Mr Johnson would adhere to the law in writing and before the judges - despite the Prime Minister's repeated public declarations that he would never request an extension.More news: Chile protests continue despite government U-turn on fare hike
"We appear to have now the numbers to get this through", Mr Raab said.