The Scottish First Minister said such a move would constitute a repudiation by the Government of a treaty “freely negotiated by it” and which was described as “oven ready” by Mr Johnson. She warned this would “significantly increase” the likelihood of a no deal Brexit.
Ms Sturgeon said: “The resulting damage to the economy will be entirely Tory inflicted. What charlatans”.
Her furious comments came as Mr Johnson’s administration appeared to have raised the stakes over this week’s post-Brexit trade negotiations.
The Prime Minister is understood to be planning new legislation that overrides key parts of the withdrawal agreement – the treaty that sealed Britain’s exit from the EU in January – in a move that could risk collapsing the trade talks.
Mr Johnson also plans to give Brussels a five-week deadline to agree fresh trade terms or otherwise call for both sides to “accept” no deal and spend the rest of the year minimising the extent of the disruption from the fallout.
He is expected to confirm his plans later today when he will insist collapsing the trade talks, should there be no agreement by the October 15 European Council, would still be a “good outcome for the UK”, allowing the country to “prosper mightily”.
Sections of the Internal Market Bill, due to be published on Wednesday, are expected to “eliminate” the legal force of the withdrawal agreement in areas including state aid and Northern Ireland customs.
READ MORE: Brexit LIVE: Boris plans to RIP UP hated Withdrawal Agreement
As part of the terms of the Northern Ireland Protocol, the region is expected to continue to follow some EU rules after the transition period ends in 2021 to ensure there is no hard border – a resolution some Brexiteers were angry about when initially revealed.
A Government spokeswoman said it was working to “protect Northern Ireland’s place in our United Kingdom”.
She said: “We are working hard to resolve outstanding issues with the Northern Ireland Protocol through the Joint Committee and will continue to approach these discussions in good faith.
“As a responsible Government, we are considering fall back options in the event this is not achieved to ensure the communities of Northern Ireland are protected.”
The suggested move, along with Mr Johnson’s comments about no deal, is likely to pile the pressure on as negotiators prepare to meet tomorrow for another round of crunch talks in London.
UK negotiator Lord Frost, in the lead up to his meetings with EU chief negotiator Michel Barnier, vowed not to “blink” as the deadline for securing a deal grows closer.
He said the UK would not be a “client state” to the EU and insisted Britain would be exiting the transition period “come what may” after December 31.
Foreign Secretary Dominic Raab said the negotiations had been “boiled down to two outstanding bones of contention” – control of UK fishing waters and the level of taxpayer support the Government will be able to provide businesses – and argued neither “principle” could not be “haggled away”.