With just 13 votes against, this easily exceeded the two-thirds threshold needed for the government to be able to overrule legislation that had required elections to be held at regular five-year intervals, beginning in 2015.
Scottish First Minister Nicola Sturgeon has said that if the "parliamentary arithmetic" supported it she would form a "progressive alliance" to keep Prime Minister Theresa May from returning to power.
Britain is set to go to the polls on June 8 after an overwhelming majority of MPs backed Prime Minister Theresa May's call to hold a general election on that date.
On Wednesday, 522 MPs voted in favour of the motion. There won't be a scheduled British general election until June 2022, eliminating the risk of an election campaign disrupting the Brexit talks. The Lib Dems now have just nine seats in Parliament.
The election will be held on June 8, almost a year after 52 percent of Britons voted to leave the European Union (EU).
"There won't be an early election", she vowed a week after the Brexit vote. With this outcome being extremely unlikely, the most one can hope for is that the election will soften the blow from Brexit. "We need a general election and we need one now", she said.More news: Devastating new poll: Majority of Americans now say Trump can't keep promises
But her decision also opens the door to more uncertainty in the region, as it now puts Europe's three most powerful nations - Britain, Germany and France - into full-throttle election mode.
Wyn Grant, politics professor at the University of Warwick, said the Liberal Democrats could regain 20 seats in the election "if things go well for them".
She said the Conservatives would provide "strong and stable leadership" for Brexit and beyond, and promising to wage "a positive and optimistic campaign".
By cynically breaking her promises, May could badly erode the public's trust in her.
Mrs May, who became PM last July after the European Union referendum, told MPs it would wrong for the United Kingdom to find itself reaching the most "difficult and sensitive" phase of Brexit negotiations in late 2018 and early 2019 when a general election was "looming on the horizon".
"Britain is leaving the European Union and there can be no turning back", asserted the British PM.More news: Canada commemorates the centenary of the Vimy WWI battle
Media captionThe moment when the vote is announced for an early general election.
Calling an early election was a "smart move", says Nicholas Wapshott in NewsWeek. Much could depend on whether a bigger majority leaves May less dependent on hardliners in her Conservative party.
May will be going into the election holding 330 of the 650 seats in the House of Commons, with a working majority of 17. The main opposition Labour Party has 229 seats, but numerous party's MPs are estranged from their leader Jeremy Corbyn. "I'm asking them to put their trust in me and if they do that, if they give me a mandate for these negotiations for the plan for Brexit that the Government has, the plan for a stronger Britain beyond Brexit that we have, then I think that will strengthen our hand", May told BBC.
"I believe in campaigns where politicians actually get out and about and meet the voters", she said. "The country is coming together, but Westminster is not".
Rachel Sylvester, a columnist for The Times newspaper, said the Liberal Democrat threat was being taken more seriously than Labour by the government. "That is what this is about", she said.More news: Celtics' Smart fined $25K for making obscene gesture