The UK government may have broken Parliamentary rules by not publishing Brexit legal advice, the Commons Speaker has said.
John Bercow said there was an “arguable case” that a contempt of Parliament has been committed.
It means MPs will debate and vote on Tuesday on whether or not to refer the case to the Standards Committee.
This is likely to delay the start of the debate on Theresa May’s Brexit deal.
Mr Bercow was responding to a call from senior MPs in six parties – Labour, the Lib Dems, the SNP, the Democratic Unionist Party, Plaid Cymru and the Green Party – for contempt proceedings to be launched.
They say the government has gone back on a binding vote to release “any legal advice in full”.
Attorney General Geoffrey Cox earlier published an overview of his legal advice on Theresa May’s Brexit deal and answered MPs questions on it.
He argued that it would not be “in the national interest” to publish his advice in full as it would break a longstanding convention that law officers’ advice to ministers is confidential.
He insisted there was no cover-up, telling MPs : “There is nothing to see here.”
By Sean Curran, Parliamentary Correspondent
The Parliamentary wrangle over the legal advice given to ministers about the Brexit deal is now coming to a head.
The Speaker’s decision to give the go-ahead for a contempt motion means that a debate over whether or not to refer a senior government minister to the Standards Committee will now be the curtain raiser to five days of debate on the Theresa May’s withdrawal agreement.
It also means that debate can’t start until the Commons has taken a decision on the contempt motion.
If there’s a vote on referring the case to the Standards Committee it could be an indication of what will happen in a week’s time, when the crunch vote on Brexit is due to take place.
If MPs refer the case to the Standards Committee, an investigation would follow.
If the committee found there had been a contempt it would recommend a sanction, anything from a reprimand to a suspension – but before that could happen, there would have to be another Commons vote to approve the committee’s findings.