Gordon Brown has warned the UK will face an “economic war” with Europe and America if Boris Johnson fails to negotiate a Brexit deal.

It comes as sources close to the UK side have said that current talks are "the last throw of the dice" from the Prime Minister in a bid to secure a deal. 

Speaking on the current Brexit discussions, former prime minister Gordon Brown said Mr Johnson’s confrontational approach will make him the “most isolated prime minister in peacetime history” in the event of a no-deal Brexit.

Negotiations between British and EU negotiators are set to resume today in Brussels in an attempt to secure a post-Brexit trade deal.

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Warning of “huge international implications” if no agreement is reached, Mr Brown said: “We would be in an economic war with Europe that would cost us very dearly.

“Food, drugs and everything else would find it difficult to get into the country without tariffs and without holdups.

“But we’d also be in an economic war with America because there’d be no chance of a trade treaty with America.

“So Boris Johnson is going to end up as the most isolated Prime Minister in peacetime history, with no friends around the world.

“Because he has simply chosen a path of confrontation when everybody knows that it’s in Britain’s economic interests – maybe not in the Brexiteers’ ideological interest – but it’s in Britain’s economic interest to get a deal and to get a deal now.”

Armistice Day 2019From left, Boris Johnson with former prime ministers David Cameron, Gordon Brown, Tony Blair and Sir John Major (Victoria Jones/PA)

Mr Brown said it would be up to Labour leader Sir Keir Starmer whether to back any deal but suggested “most of the big questions” are likely to remain unanswered even if an agreement is reached, leading to “an unstable relationship” over the coming months and years.

He predicted that there will be a tariff-free trade deal without quotas but said the EU may insist upon sanctions and tariffs being imposed if the UK breached the “level playing field”.

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“So you may have an unstable relationship over the next few months or even over the next few years because all they can get to in this negotiation is a minimalist deal, which leaves people very uncertain about the path of the economy”, Mr Brown said.

Shadow Cabinet Office minister Rachel Reeves said: “Government sources overnight are saying it’s the last throw of the dice – I just say to the Prime Minister, this is not a game of snakes and ladders.

“This is about people’s jobs, about people’s livelihoods, the Government has got to deliver on the promises they have made and we will hold them to it.”

Ms Reeves said Boris Johnson should “get on and deliver” on his promises of a Brexit deal to enable the country to “move on”.

Asked on the BBC’s Andrew Marr Show if Labour would back any agreement on the future relationship, Ms Reeves replied: “Let’s see. At the moment the priority is to get a deal but we’ll have to look at the content of a deal but also any legislation that comes to Parliament.

“We’re not going to give them a blank cheque but I think I have been very clear both today and on previous programmes with you, Andrew, that the most important thing is the Government gets a deal.”

Ms Reeves was repeatedly pressed about Labour’s position, to which she replied the Opposition wanted to see the content of any deal.