Video report by ITV News Political Editor Robert Peston
The Liberal Democrats put a pledge to offer the British people a second referendum on Brexit at the heart of their manifesto.
The party says they would offer a fresh vote - including the option to reject Brexit - after the terms of the deal are made clear.
It has also laid out plans for major boosts to NHS and schools funding and said they would work to build 300,000 new homes a year.
Much of the extra cash for their plans would be raised through a 1p increase on income tax and raising corporation tax by 1% to 20%.
Leader Tim Farron said the they offered a "brighter future in a fairer Britain" and a chance to reject the "extreme version of Brexit" pushed by Theresa May and Ukip's Nigel Farage that would "wreck the future" of the UK.
Mrs May's decision to pull Britain out of the single market was not on the ballot paper last year and any final Brexit deal should be subject to a second referendum, he said.
"That decision alone is a time bomb under our economy," warned Mr Farron. "And when it blows up it is going to take our NHS and our schools down with it. It is going to wreck our children's future for decades to come."
The party's manifesto, published today, includes the key pledges to:
Offer Britons the final say on Brexit with a second vote after the terms of an exit deal are made clear.
Provide an extra £6 billion per year on the NHS, care services and public health, to be paid for by a 1p rise on income tax.
Give nearly £7 billion extra for schools and colleges including protecting per-pupil funding in real terms.
Almost double housebuilding to 300,000 new homes every year and give first-time buyers the option to 'rent to buy'.
Scrap the Conservative benefits freeze and reverse cuts to a number of benefits and entitlements.
Maintain the ‘triple lock’ on the state pension.
Reduce the voting age to 16.
You can read the full manifesto here:
Mr Farron told ITV News Political Editor Robert Peston that the Labour had failed to offer any real opposition to a hard Brexit and the people should have a "right to have the final say".
He added that Theresa May was currently heading for a "landslide" win that would be interpreted by the Tories "as an endorsement" for an attack on on education and health services.
The party said it would raise most of its funding through tax increases - but would initially have to borrow extra cash to meet spending needs.
It expects to raise an extra £6 billion each year through a 1p increase on income tax, along with £3.6 billion through a corporation tax increase and £2.5 billion through a crackdown on tax avoiders.
Liberal Democrats also back the legalisation of cannabis and say that taxes on sales of the drug could raise a further £1 billion.
Despite all these measures, they accept that the budget would run a deficit initially and would require an extra £5 billion of borrowing in 2018-19.
They say the budget would be balanced for day-to-day spending by the following year - though the UK would still borrow cash for major one-off capital infrastructure projects.
The Lib Dems also pledged to reduce the deficit but aim for balanced growth rather than prioritising sharp cuts to public debt.