Labour say they would scrap Theresa May’s Brexit plans and unilaterally guarantee the rights of EU residents before talks start, if they win power.
While accepting the UK was leaving, Shadow Brexit Secretary Keir Starmer said Labour would press for a different deal prioritising jobs and work rights.
It would also seek an early deal on transitional arrangements to smooth the way for the UK’s departure in 2019.
The Conservatives said only they had a clear plan for exiting the EU.
Ahead of a campaign visit to Wales on Tuesday. Theresa May said the Brexit vote should have been a “wake-up call for a generation of politicians who have taken the people for granted for too long” but instead other parties had “closed ranks”.
Labour, most of whose MPs backed a Remain vote in last year’s referendum, is in a fight to hold onto seats in Leave-voting constituencies on 8 June.
The Conservatives are hoping to take seats from Labour in areas which voted to leave the EU, including the Midlands, the north-east and north-west of England and across Wales, with a message that it is implementing the will of the people expressed in last year’s vote.
Labour has been criticised by, among others, former prime minister Tony Blair, for what he says is a lack of clarity in its approach to Brexit.
Unlike the Lib Dems, it has ruled out a second referendum, but suggested Parliament could stop a so-called “hard Brexit”.
In Labour’s first major policy statement on the issue of the election campaign, the party is signalling that it would take a different approach to the two-year process of negotiating the EU’s exit – expected to start in earnest in June.
It would scrap Theresa May’s Brexit plan – outlined in a White Paper in February – which envisages leaving the single market and customs union.
Instead, it will focus on delivering a deal which “retains the benefits” of single market and customs union membership.
On immigration, a Labour government would on its first day in office guarantee the legal status of the three million EU nationals living in the UK to correct what it says is a “shameful injustice”.
It would then press for reciprocal guarantees for the 1.2 million Britons living on the continent.
In a further break from the government’s policy, Labour says leaving the EU without a deal would not be a “viable option” – although it is not clear whether its promise of a “truly meaningful” vote in Parliament on the final deal would amount to a potential veto.
In addition, it would replace the government’s proposed Great Repeal Bill – which would scrap the 1972 European Communities Act and transpose the myriad of existing EU law applying to the UK into domestic law – with an EU Rights and Protections Bill.
‘For the many’
It insists there can be no “rolling back” of workplace protections, environmental standards and consumer rights acquired through EU membership and the Bill will not include any measures to limit the lifespan of laws or directives, such as sunset clauses.
“This will make sure that all EU-derived laws are fully protected without qualifications or limitations,” Sir Keir Starmer will say.
“A Labour government will never consider these rights a burden.”
Labour would negotiate with the remaining 27 EU members in the interests “of the many, not the few”, he will claim.
“We will approach negotiations in a completely different way to a Tory Brexit.
“We will scrap the government’s Brexit White Paper and replace it with fresh negotiating priorities that reflect Labour values.
“The White Paper will have a strong emphasis on retaining the benefits of the single market and customs union, as Labour knows that is vital to protecting jobs and the economy.”
Labour has previously set out six tests for a successful Brexit – including maintaining a strong, collaborative relationship with the EU, protecting security co-operation, delivering for the whole of the UK and introducing a fair immigration system.
In response, the Conservatives said Jeremy Corbyn was a “weak leader of a divided party who could not get the right deal for the UK”.
“We have a clear plan for the Brexit negotiations, and every vote for Theresa May will strengthen her hand in those negotiations to get a good deal for the UK,” said MP and former minister Dominic Raab.
“Only Theresa May and the Conservatives can provide the strong and stable leadership the United Kingdom needs to see us through Brexit and beyond.”
In a fresh intervention on Tuesday, Mr Blair said the Conservatives’ position on Brexit must be “turned against them”.
Writing in the Guardian, he warned Mr Corbyn “this is not the time to fight a conventional partisan election”.