Tim Farron and Theresa May went head-to-head in the Commons today
The party leader vowed to not only speak for the 48 per cent who voted Remain in last year’s referendum – but also those who think Mrs May’s approach to Brexit is wrong for Britain.
And he even admitted he would not rule out working with other parties to try and stop the ‘hard’ European Union exit.
But Mr Farron insisted the only “plausible” way of blocking a Conservative majority would be through Lib Dem gains.
The leader launched the party’s campaign in Richmond Park alongside MP Sarah Olney, who unseated Zac Goldsmith to snatch the Remain-voting constituency in a December by-election.
Today MPs approved the June 8 election
And the location seemed to reflect the party’s ambition to recover seats lost to the Tories in 2015.
But despite the furore caused by former leader Nick Clegg in 2010, when he was accused of “jumping into bed” with the Tories, Mr Farron has not ruled out working with any party or politician to further his anti-Brexit ambitions.
Senior Lib Dem sources indicated they would be happy to accept support from pro-EU figures including Labour's Chuka Umunna or even campaign with former PM Tony Blair.
And Green co-leaders Caroline Lucas and Jonathan Bartley have already written to Mr Farron and Labour leader Jeremy Corbyn calling for discussions on some form of anti-Tory pact.
Theresa May announced yesterday she was calling a snap general election
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Theresa May will get the coronation she assumes she's going to get unless the Liberal Democrats grow and are strong
Liberal Democrat leader Tim Farron
Asked whether he was ready to contemplate a pact with Greens, Mr Farron said: "I very much enjoyed working with Caroline Lucas during the referendum campaign.
“She’s somebody I've got a very high regard for, I think is a very powerful voice in Parliament.
"I think it's worth saying though … the only plausible route of any kind towards the Conservatives not winning a majority is the Liberal Democrats group."
Politicians react to Theresa May's snap general election Wed, April 19, 2017
UK Prime Minister Theresa May has announced her intention to hold an early general election on June 8
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Theresa May has called for a snap general election
But ex-minister Sir Vince Cable, who is fighting to regain his former Twickenham seat on June 8, said there was "no prospect" of an electoral deal with Labour under Mr Corbyn's leadership.
Sir Vince told BBC Radio 4's Today programme the aim was "to get a substantial bloc of MPs into Parliament so that we can substantially affect the Brexit outcomes, hopefully stop a bad outcome if that's what happens".
He added it was “utterly remote to believe that Jeremy Corbyn could become Prime Minister”, and could not see any kind of coalition under his embattled party.
While Mr Farron cited the SNP's "national ceiling" and claimed it would be "arrogant" to assume anything other than Labour shrinking in size.
Tim Farron warned Lib Dem gains would be the only way to stop Brexit
He added: "Those two things will mean Theresa May will get the coronation she assumes she's going to get unless the Liberal Democrats grow and are strong.
"That means us being independent. It means us speaking for those people who don't just believe they were right to vote Remain last June, but those who voted Leave and think it is wrong that the country is being taken in this radical direction for an extreme version of Brexit that wasn't on the ballot paper.
"We know that the only votes in this election that will help us to fight against a hard Brexit and to keep us in the single market, and indeed will build a strong and decent opposition we desperately need in this country, is a Liberal Democrat one."
Meanwhile, former Lib Dem leader and deputy prime minister Nick Clegg confirmed he will seek to retain his Sheffield Hallam seat in the coming election.