Boris Johnson is planning to rip up key parts of the Brexit withdrawal agreement putting at risk trade talks with the European Union.
The Mirror has learned the Prime Minister intends to use domestic legislation to override the “oven-ready” Brexit deal he signed with the EU at the end of last year.
The high stakes move would be a breach of international law and could damage the UK’s reputation on the international stage.
Government insiders also suggested it would give the UK a pretext later this week to blow up trade deal talks in favour of an Australian-style relationship.
Mr Johnson will on Monday claim that leaving without a trade deal would still be a “good outcome” for the UK – despite the hammer blow it would deliver to the economy.
Sources told the Mirror the Government was weighing up plans to rewrite the Northern Ireland protocol, which leaves the region with a foot in both EU and UK customs territories in order to avoid a hard border.
Ministers plan to use the internal market bill, which comes before the Commons on Wednesday, to force changes to the withdrawal agreement amid concerns among pro-Brexit MPs that it could keep the UK permanently tied to EU law.
They would aim to remove any legal powers Brussels may retain in the region over areas including state aid and customs.
The FT reported that the finance bill after the Budget this autumn would then be used to overwrite the payment of tariffs on goods entering Northern Ireland.
One source told the paper: “The move would “clearly and consciously” undermine the agreement on Northern Ireland that Boris Johnson signed last October to avoid a return to a hard border in the region”.
Ireland’s foreign minister Simon Coveney warned: “This would be a very unwise way to proceed”.
Shadow Northern Ireland Secretary Louise Haigh added: “The ‘oven-ready’ Brexit deal the Prime Minister promised the British people was yet another example of his fluid relationship with the truth.
“Just 10 months after signing a treaty promising to implement the Northern Ireland protocol, Boris Johnson’s government is already threatening to renege on the UK’s legal obligations.
“This would be an act of immense bad faith: one that would be viewed dimly by future trading partners and allies around the world and make it more difficult for us to hold other governments to account.”
Mr Johnson will on Monday issue Brussels with an October deadline to reach a post-Brexit trade deal.
He will warn the European Union that unless agreement can be struck by a key summit next month both sides should “accept that and move on”.
But EU insiders have warned that the UK will have to offer further concessions if it wants to avoid a damaging no deal departure.
The UK’s chief Brexit negotiator has said the Government is “not scared” of walking away from talks without an agreement ready to come into force in 2021.
And Foreign Secretary Dominic Raab warned the UK would not “haggle away” the two remaining stumbling blocks – fishing and the level of state aid for businesses.
Ahead of the latest round of talks on Tuesday, Mr Johnson will claim that time to strike a deal is running out.
He will say: “We are now entering the final phase of our negotiations with the EU. The EU have been very clear about the timetable. I am too.
“There needs to be an agreement with our European friends by the time of the European Council on October 15 if it’s going to be in force by the end of the year.
“So there is no sense in thinking about timelines that go beyond that point.
“If we can’t agree by then, then I do not see that there will be a free trade agreement between us, and we should both accept that and move on.”
The PM’s Brexit chief Lord Frost, said to be the architect of the plan to overwrite the withdrawal agreement, said the UK would leave the transition arrangement – which sees it follow many EU rules – “come what may” in December.
But he was accused by Theresa May’s former Number 10 chief, Lord Barwell, of having a “brass neck” after he said the former PM’s negotiators had “blinked and had its bluff called at critical moments” during talks over the Brexit deal.
Mr Raab has claimed a trade deal with Brussels was “there for the taking” as the Government stepped up pressure on the EU to give way.
He described a deal as “win-win” and argued that it would avoid the “damaging impacts” of a no-deal fallout on both sides of the Channel.
But Brussels’ chief negotiator Michel Barnier has said he is “worried and disappointed” about a lack of concessions from the UK.