Members of the House of Commons voted 328 to 301 to take a crucial first step toward forcing Johnson to delay Brexit by three months in an effort to stop a no-deal split - a delay he has repeatedly rejected under all circumstances.
Johnson attempted to quell rumours of a General Election by telling the nation he does not want another vote.
However, it is not certain he will succeed as it requires the support of two-thirds of MPs - and the opposition Labour party is deeply distrustful of Johnson's motives.
MPs are racing to get it through before parliament is suspended next week, in what Labour leader Jeremy Corbyn said "may be our last opportunity" to prevent a chaotic Brexit.
But with the clock ticking, the European Union said Tuesday it had received no proposals from the British government aimed at overcoming the impasse in Brexit talks.
A cross-party alliance defeated Boris Johnson in parliament on Tuesday in a bid to prevent him taking Britain out of the European Union without a divorce agreement - prompting the prime minister to announce that he would immediately push for a snap election.
Johnson's opponents are putting forward a bill that would force him to delay Brexit until January 31.
"The prime minister has lost his majority with the honorable member from Bracknell joining the Liberal Democrats", she said on the chamber floor, adding: "When will the prime minister stop playing with people's lives and stop Brexit?"More news: Priyanka Chopra Walked Her Dog in This Glamorous Denim-on-Denim Look
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He said the move by opposition MPs and members of his Conservative Party to try to delay Brexit beyond October 31 if he can not agree exit terms with Brussels was like "running up the white flag".
An early election could give Johnson a majority, although it is also a big risk, as the political landscape was deeply fragmented by the 2016 referendum. He says this would undermine his negotiating hand and he'd rather collapse the government and hold a fresh election.
Speaking 80 years on from the day Britain entered World War II, Johnson said "this country still stands then as now, for democracy, for the rule of law".
But he remains in government until he loses a formal confidence vote, or calls an election.
Meanwhile, a court in Edinburgh heard a legal challenge Tuesday against Johnson's decision to suspend Parliament next week for more than a month, which critics said was an attempt to silence MPs. It was trading as low as 1.1965 against the USA dollar in early morning, marking its lowest level since a flash crash in October 2016 when the currency briefly fell sharply to 1.15 against the US dollar before rapidly rebounding.
As protesters on the streets outside Parliament denounced a "coup", the lawmakers turned to a key piece of legislation that would prevent an immediate no-deal Brexit.
The comments were met with widespread jeers from fellow MPs, given Johnson has recently asked the Queen to prorogue parliament until October 14 and threatened Conservative MPs with deselection for opposing his Brexit strategy.
British Prime Minister Boris Johnson, seen hosting health service workers Tuesday at No. 10 Downing St.in London.