London (AFP) - Britain's pro-European campaigners lost their bid Friday to persuade the public to undo Brexit, suffering a devastating defeat to the right-wing ruling party.

Prime Minister Boris Johnson's Conservatives secured their biggest majority since the heyday of Margaret Thatcher in the 1980s in Thursday's snap general election.

The outcome allows Johnson -- a figurehead of the original 2016 EU membership referendum -- to push through his divorce deal with Brussels through parliament and take Britain out of the bloc on January 31.

"With a majority, Boris Johnson will now be able to pass his Withdrawal Agreement Bill and formalise Brexit," said Matthew Goodwin, professor of politics at the University of Kent.

"The battle for Brexit is over."

The scale of Johnson's victory was a crushing disappointment for the smaller Liberal Democrats, who led the charge of the "remainers" against Brexit.

They caught fire in May's European Parliament elections, storming to a second-place finish and setting their sights on a similar performance in Westminster.

But instead of making gains, the Liberal Democrats lost a seat, reducing their share of vote]s in the 650-member House of Commons to 11.

The party said Friday it would elect a new leader after Jo Swinson was defeated in her Scottish constituency.

Split vote

Experts said the party's pledge to cancel Brexit altogether without a vote if it was elected was unpopular. Even some pro-EU supporters believed it was undemocratic.

"I do think the 'revoke Article 50' was a disaster," said Simon Hix, a political scientist at the London School of Economics. 

"They already had all the hardcore remainers, they weren't going to get any more."

He added: "She (Swinson) completely alienated Remain Tories... A lot of those reluctant remainer Tories have gone and voted for Johnson."

Labour, which was criticised for a non-committal position on Brexit, appeared to offer no alternative, particularly with its leader Jeremy Corbyn such a divisive figure.

The party offered to renegotiate Brexit with Brussels and put their deal to a public vote alongside an option to remain. 

But Corbyn said he would remain neutral, while wider criticism about his leadership, particularly over claims of anti-Semitism in Labour, appear to have been a turn-off.

Attempts at tactical voting -- touted as a way of returning pro-EU parties -- also  failed, despite claims of a large turnout, particularly of young voters.

'Remain' to 'Re-join'

Tony Travers, from the department of government at the London School of Economics, attributed the failure of "remain" to a split in the vote between opposition parties.

Instead, Johnson's Tories had the bulk of the Leave vote, he told AFP.

"The pro-Brexit Leave vote was always a bit more determined than the Remain vote. The Leave vote just wanted to go, didn't like the EU. That's played itself out again tonight.

"In the end, the Leave vote is more solid and more committed."

Johnson -- who campaigned largely on a pledge to "Get Brexit Done" -- issued a call for unity after more than three years of deadlock.

British politics has become increasingly polarised since the 2016 referendum that saw 52 percent vote to leave the EU.

But determined pro-Remain supporters, who are well-represented in the media and the political establishment, are likely to continue their campaign -- but for Britain to rejoin the EU.

"The campaign for a second referendum is as dead as a doornail," said Travers.

"'Remain' will be forced to evolve into 'Re-Join'," added Goodwin, but he warned that was "a much harder, longer and even generational struggle".