MPs have defeated the Government and voted to take control of Parliament in a bid to stop a no-deal Brexit.
Parliamentarians secured 328 votes for the amendment, whilst 301 voted against it - giving a majority of 27.
The Prime Minister has confirmed he will now seek to trigger a snap general election and accused Parliament of being "on the brink of wrecking any deal" with the EU.
The vote, following a motion put down by Tory rebel Sir Oliver Letwin, means MPs opposed to a no-deal departure from the European Union will be able to dictate the order of business for Wednesday in the Commons.
Their hope is to push through legislation which would ultimately delay the UK leaving the EU until a deal can be agreed and signed off by both Brussels and Westminster, or MPs vote for a no-deal exit.
The PM started the day with a slim majority, which then fell into a minority when Tory MP Phillip Lee defected to the Lib Dems.
Mr Johnson's allies are set to be further depleted after 21 MPs expect to be booted from the Conservatives after rebelling.
PM warns over 'wrecking deal' as Corbyn pushes election
After the Government's defeat, Prime Minister Boris Johnson said he will be tabling a vote on an early general election on Wednesday.
He said: "The consequences of this vote tonight means that Parliament is on the brink of wrecking any deal that we might be able to get in Brussels.
"It will hand control of the negotiations to the EU."
He continued: "I don't want an election but if MPs vote tomorrow to stop the negotiations and to compel another pointless delay of Brexit, potentially for years, then that will be the only way to resolve this.
"I can confirm that tonight we will are tabling a motion under the Fixed-term Parliament Act."
In response to Mr Johnson's call for a general election, Labour leader Jeremy Corbyn said his party would not support the move until chances of a no-deal Brexit were taken off the table.
He added that the vote to take control of Parliament showed "there is no consent in this House to leave the European Union without a deal.
"There is no majority for no-deal in the country.
"As I have said before: if the Prime Minister has confidence in his Brexit policy - when he has one he can put forward - he should put it before the people in a public vote."
Lib Dem leader Jo Swinson also warned the Commons to "act responsibly" over any vote on a general election.
"It is vital that this House acts with responsibility and does not tip our country into an election at a point where there is any risk that we will crash out of the European Union during that election campaign or immediately after," Ms Swinson said.
The SNP's Westminster leader, Ian Blackford, said Mr Johnson has an "impressive" 100% defeat rate as Prime Minister, and that he should "start acting like a Prime Minister should".
Mr Blackford said he does not believe that Mr Johnson has an alternative Brexit plan and called for a Bill to take no-deal off the table on Wednesday.
He added: "It is a fantasy that a new Brexit deal is to come - let us have an election."
Conservative Party ousting rebels in vote aftermath
Tory MPs who voted against their leader will now be expelled from the party, Downing Street has confirmed.
MPs who have been in their roles for decades find themselves ousted.
Ken Clarke, known as Father of the House, the longest standing MP has been kicked out of the party.
As has Philip Hammond, who until a few weeks ago was Chancellor, and Nicholas Soames - the grandson of Winston Churchill, who advocated for a cross-border alliance to bring security to the EU.
Sir Nicholas told BBC Two's Newsnight that he will not stand in the next election.
A source close to the rebels said: "Tonight's decisive result is the first step in a process to avert an undemocratic and damaging no deal.
"No 10 have responded by removing the whip from two former chancellors, a former lord chancellor and Winston Churchill's grandson.
"What has has happened to the Conservative Party?"
Former Attorney General Dominic Grieve, who was told on Tuesday evening he had been removed from the party roster, said this is "a very dangerous moment for the Conservative Party.
"I look at the emails I'm getting from Conservative voters saying they'll never vote Conservative again."
Others kicked from the party include Justine Greening, who ran education between 2016 and 2018, and Sam Gyimah, who stood in the leadership race to run the Tory party but dropped out in the early stages.
In all, 21 MPs expect to be booted from the Conservative Party, significantly reducing the Prime Minister's majority into negative figures.
ITV News Political Editor Robert Peston says "nobody alive has lived through this kind of collapse in the way that governments operate".
What is going to happen now?
The Prime Minister has said he now plans to send Britain to the polls in a general election, which the House of Commons will have to approve.
Despite seeking an election, Mr Johnson hadrepeatedly said he does not wish to call one, but has been left with little choice.
Under the Fixed Term Parliaments Act, introduced by the Cameron administration eight years ago, two-thirds of MPs (434) must agree to back a general election for Britain to head to the ballot box.
It doesn't matter how many people vote in total - the Act means that 434 MPs must vote for an election for polling stations to open.
Mr Johnson would need Labour to back a general election for it to happen, since the party has 247 MPs in the Commons.
Despite Mr Corbyn saying his party would only back it if no-deal was taken off the table, Labour, like the Tories, are also deeply divided over Brexit.
ITV News Europe Editor James Mates says that on the continent, the voting intentions of parliamentarians are being closely watched as a guide to how Brexit - and the future leadership of the UK - may now play out
If the election does go ahead, it's likely to be held on Tuesday, October 15- the first time it won't be held on a Thursday since the 1930s.
The original date mooted for the ballot was to be the day before, but this has been revised.
The change is, according to a Government source, as a Jewish festival held on that day would compromise the voting availability of those celebrating it.