In a sign of the anger and division Brexit has sown among politicians, the motion prompted bad-tempered scenes in Parliament, as Conservatives accused Speaker John Bercow of contravening parliamentary convention by allowing a vote on the amendment.
"If that is a choice then I say let's go on WTO rules".
With less than three months before Britain is due to leave the EU, Parliament kicked off a five-day battle over May's Brexit plan with a show of force - undermining her preferred timetable if lawmakers vote down her deal on Tuesday.
"Obviously, the next thing to do immediately after that is for there to be a vote of confidence in the government", he told BBC Radio 4.
Sir Oliver Letwin, a former minister in David Cameron's government who has never previously rebelled over Brexit, said that it was a signal to hard Brexit supporters that MPs would block a "no deal" scenario.More news: Fiji Water Girl steals the limelight at the Golden Globes
No Conservative or Leave-supporting MP believed that the United Kingdom was likely to rejoin the European Union in the next 20 years, while 50% of Labour MPs and 37% of Remain voters believed it would be.
If Brexit is all about taking back control, MPs appear to have finally taken it to heart.
"We are talking about 79 days until potentially crashing out of Europe without a deal - should our focus not be on the detail and the arguments about the process in this place, but getting on with a plan B if Parliament decides the government's plan is not the one for the people?".
The MPs also won support for a motion that will force the government to seek parliamentary approval for some spending plans if Britain leaves the European Union without a Brexit deal.
"I think he stepped way over the mark out today he's broken with parliamentary precedent".
"It is a warning to the Government not to drift into No Deal at the end of March by accident or through brinkmanship", she said.More news: Trump uses televised address to try to create a border crisis
"When I became an MP three years ago I was determined that I would not become part of the establishment".
He later yelled "ridiculous" and "that is utter sophistry", but Mr Bercow defended his decision.
She set out further clarifications she hopes will win over her own Conservative MPs and Northern Ireland´s Democratic Unionist Party (DUP), which props up her government in parliament.
Since being elected in 2009, he has angered many Tory MPs for his handling of business and treatment of MPs, but he also has many admirers, particularly on the Labour benches, who believe he has transformed the way Parliament holds the executive to account.
He said: "That sticker on the subject of Brexit happens to be affixed to or in the windscreen of my wife's vehicle, and I'm sure he wouldn't suggest for one moment that a wife is somehow the property or chattel of her husband".
Mr Bercow said he had consulted privately with the clerk and other officials, but did not confirm his decision was taken with agreement from Sir David.More news: Alvaro Morata Edging Closer To LaLiga Return
"We're all focused in the government on winning parliamentary support in the vote that's coming up next week", he told reporters as he arrived at the meeting in Brussels.