Theresa May was accused of “misleading the House of Commons” by the SNP over the Irish backstop after the full Brexit legal advice was published.
The party’s Westminster leader Ian Blackford made the allegation during heated and hostile exchanges during Prime Minister’s Questions.
He said Mrs May had been “concealing the facts on her Brexit deal”, saying the Withdrawal Agreement would allow Northern Ireland to remain in the EU’s single market – while Scotland could not.
Mr Blackford mocked the PM for having lost three votes on Tuesday and being found in contempt of Parliament, saying: “We were promised strong and stable – what we’ve got is a Government in crisis.”
The MP for Ross, Skye and Lochaber then asked: “Is it time that the Prime Minister took responsibility for concealing the facts on her Brexit deal from members in this House and the public?
“Will she take responsibility?”
Mrs May rejected the claim, and said the full legal advice they were forced to publish contained the same arguments as the shortened version the Government made available earlier this week.
Mr Blackford called that an “incredibly disappointing response”, and suggested the release of the full legal advice showed that: “Since the Prime Minister returned from Brussels she has been misleading the house, inadvertently or otherwise.”
This led to a prolonged period of shouting across the chamber, with Tory MPs calling for him to withdraw the comment.
Commons Speaker John Bercow rebuked Mr Blackford, saying there could be no “ambiguity” in comments to suggest that the PM had purposefully misled the House.
This led Mr Blackford to alter his wording to say she had done it “perhaps inadvertently”.
But this failed to dampen the jeers from the Tory benches and Mr Bercow asked to him to again “rephrase” his argument. However, he continued in the same vein.
In response, Mrs May said the copy of the full legal advice he was holding was “no different” to the statement the Attorney General Geoffrey Cox made on Monday.
She added: “I have myself said on the floor of this House that there is indeed no unilateral right to pull out of the backstop.
“What I have also said is that it is not the intention of either party that a) the backstop should be used in the first place, or … b) that if it is used, should be anything other than temporary.”