Liberal Democrat leader Tim Farron has promised to issue a second EU referendum if his party is elected during this year's General Election.
He warned that the impact of a hard Brexit will disadvantage future generations to come.
His party's manifesto says should the Liberal Democrats be fortunate enough to form the next government of the United Kingdom, the public will be provided with a final say over the EU deal.
'A ticking time bomb'
Mr. Farron warned voters leaving the EU's Single Market will have a devastating effect on schools and hospitals, comparing it to a ticking time bomb.
He promised party supporters only the Liberal Democrats will do everything in their power to oppose a hard Brexit.
The Liberal Democrat leader said there would be an option of remaining in the EU on the ballot paper should a second referendum become a reality.
He fought back against allegations from his opponents that he has failed to accept last year's result on June 23rd, saying it is better for Britain to remain in the EU.
Mr. Farron urged the public to help fight for Britain's future in Europe.
He said he does not blame people who opted to leave the EU for the Conservatives' pursuit of a hard Brexit whilst arguing Labour is split over the issue.
He also blamed Theresa May for alienating other European nations since she came to power.
Mr. Farron urged voters to not feel obliged to opt for one of the two main parties, and instead said having more Liberal Democrat MPs in Parliament will ensure Britain gets a good EU deal.
'A bid to end austerity'
Other measures included pouring billions of pounds into the NHS by increasing income tax by 1p in the pound, restoring the 20% corporation tax rate, ending the married couples' allowance and cutting the lower rate of inheritance tax.
In a bid to end austerity in the UK, this position stands in stark contrast to that of Nick Clegg's, who supported the Conservatives' economic plans whilst serving as deputy prime minister.
The Conservatives said there is little difference between Labour and the Liberal Democrats over increasing taxes.
Mr. Farron said he intends to strike a balance between public spending and paying off the national debt.
On Brexit, the Liberal Democrat leader is not optimistic Britain will achieve better trade deals than the one the EU currently offers all member states.
He said this is a once-in-a-lifetime battle to save this country's future.
After losing 50 seats in the 2015 General Election, Mr. Farron hopes he can claw back seats by positioning themselves as the anti-EU party to people anxious about Brexit.
This strategy worked in the Richmond by-election last year when Liberal Democrat Sarah Olney defeated the then incumbent Conservative MP, Zac Goldsmith, who resigned in opposition to the Government's plans for Heathrow expansion.
They also did the same in the Witney by-election after David Cameron resigned as the MP there in opposition to Theresa May's plans to reintroduce grammar schools.
Conservative MP Robert Courts won the seat, but the Liberal Democrats cut Mr. Cameron's majority of 25,155 down to 5,702.
'No coalitions'
Mr. Farron has said there will be no coalitions with the Conservatives or Labour in a bid to avoid repeating the Liberal Democrats' share of the vote collapse, as it did in 2015.
The pro-Brexit group Leave Means Leave said the Liberal Democrats' Brexit position was unpatriotic and anti-democratic.
The SNP said their position is contradictory as Scotland cannot stay in the EU whilst remaining a member of the United Kingdom.
This is not the first attack against the Conservatives' EU policy from their former coalition partners.
The Liberal Democrats' Brexit spokesman, Nick Clegg, has recently said the Prime Minister is robotic and brittle.
He added she will fail in upcoming EU negotiations.
Mr. Clegg accused his former Coalition colleague of 'Nixonian paranoia' over the EU's negotiating strategy.
He said there was little difference between the Tories and UKIP in this general election.