VIDEO: Labour's Brexit strategy in 60 seconds

Shadow Brexit secretary Sir Keir Starmer said the option of remaining in a reformed EU customs union should be part of divorce negotiations.

"What we should do is make sure we have got options on the table, not take options off the table. And the customs union is a classic example. There is anxiety across the manufacturing sector about the impact of simply walking away from the customs union.

"If we leave it on the table, it may be in a year, or two years, that doesn't work - but why take options off the table before you have even started negotiations?"

Pressed on whether this could mean abandoning Britain's ability to cut non-EU trade deals, Sir Keir said: "We have to get the right deal with the EU. We need to recognise that we have 44% of our trade with the EU. That is the number one consideration.

"We are talking about the opening stance, not where we will end up. Sensible negotiations start by leaving the maximum number of options on the table."

Sir Keir said that in seeking a "reformed" relationship with the single market, or customs union, Labour accepted that rules on free movement of workers could not continue as immigration had been such a major factor in the Leave referendum victory.

In a speech in central London, he said he would like Parliament to have a "meaningful" vote on any withdrawal deal late next year, adding that a Labour government would then have time to renegotiate an agreement if MPs rejected what was on offer.

Sir Keir said there would need to be an end-date for such renegotiations, and Britain would switch to emergency transitional arrangements once it exited the EU in order to avoid an economic "cliff edge" if no deal was in place.

He insisted that leaving the EU without a deal would be "reckless" and represent the worst outcome for the UK.

EU nationals would have their right to remain in the UK guaranteed on day one of Jeremy Corbyn taking power, and the Labour leader would then "seek" reciprocal measures for Britons living in the rest of the bloc.

Sir Keir said: "I am absolutely convinced that that gesture would unlock this impasse and guarantee for our citizens across the EU, exactly the same rights."

Cutting immigration will not be the main priority of a Labour government's plans for Britain's future outside the European Union, he said.

"We recognise that immigration rules will have to change as we exit the EU, but we do not believe that immigration should be the overarching priority."

When asked if Labour completely ruled out a second Brexit referendum, Sir Keir said he would expect transitional arrangements to lead to a final deal in five or six years' time, adding: "At that stage we will have left the EU three or four years earlier, and therefore the second referendum argument simply doesn't hold water."

Labour intends to ditch the Government's Great Repeal Bill, which Sir Keir claimed would harm protections for workers as well as environmental safeguards.

"We do not believe that leaving the EU means severing our ties with Europe. We do not believe that Brexit means weakening workers' rights and environmental protections or slashing corporate tax rates."

Responding to Sir Keir's speech, Brexit Secretary David Davis said: "Jeremy Corbyn is too weak and floundering to get a good deal in the Brexit negotiations.

"A divided Labour Party, propped up by a Liberal Democrat/SNP coalition of chaos, can't even agree amongst themselves on Brexit. Putting this chaotic team in charge of negotiating with the EU would be a dangerous risk to Britain's future."