John Bercow, the Speaker, allowed Labour, the DUP and four other opposition parties to lay down a motion that will be voted on on Tuesday, immediately before before the start of the five-day debate on the Brexit deal.
The motion, submitted late on Monday, calls on MPs to find “ministers in contempt for their failure to comply” and is signed by the shadow Brexitsecretary, Sir Keir Starmer; the DUP’s Westminster leader, Nigel Dodds; and the Scottish National party, Liberal Democrats, Plaid Cymru and the Green party.
No penalty is spelt out in the motion, which is intended to act as a final warning, but Labour said that if it was passed on Tuesday and not still complied with then the party would seek further sanctions.
The party indicated it would then seek to hold a senior minister – likely to be either the Cabinet Office minister, David Lidington, or the attorney general, Geoffrey Cox – in contempt and seek their suspension from the Commons.
Bercow ruled in the evening that he would accept a contempt motion after the six parties wrote to him jointly complaining that the summary Brexit legal advice released on Monday did not comply with a Commons resolution agreed on 13 November.
The Speaker declared on Monday night that there was “an arguable case that a contempt has been committed” after Labour and others complained that “the information released today does not constitute the final and full advice provided by the attorney general to the Cabinet”.
Panicked Conservatives flooded the Commons chamber late into the evening to filibuster a debate on Scotland’s foreign policy footprint, to give their party’s whips time to submit their own amendment to the contempt motion.
Downing Street declined to respond on Monday night, but the governing party put down an amendment seeking to refer the matter to the Commons privileges committee, in an attempt to kick it into the long grass.
The Speaker accepted the plea from the combined opposition parties after a fractious two-and-a-half-hour debate in which Cox repeatedly refused to release the full legal advice on the Brexit deal he had provided to cabinet.
The row is likely to overshadow the first day of the five-day debate, which May intends to lead in her increasingly fraught attempt to get her Brexit deal endorsed by parliament.
Cox conceded in Monday’s debate that he was at risk of being declared in contempt of parliament for his actions when he became the first attorney general for 40 years to appear before MPs to take questions.
The government’s chief legal officer said MPs must decide “whether or not an attorney general, seeking to protect the public interest” was in contempt. He said he had “sought to comply with the spirit of it to the maximum degree” by putting himself before MPs and publishing a 45-page summary earlier in the day.
Ominously for May, some hard-Brexit MPs said they were unsatisfied by the decision to defy an earlier Commons resolution calling for full publication.
Jacob Rees-Mogg accused Cox of not explaining why ministers were refusing to comply with the Commons motion. “It is no longer a matter for the government to judge; it has been decided by this house, which is a higher authority,” he said.
On 13 November, the Commons unanimously agreed to a motion put down by Labour calling for the legal advice on the Brexit deal to be published “in full”. Conservative MPs were told to abstain after it became clear that the government was not certain of winning the vote when the DUP said it would vote with Labour.
Cox told the Commons on Monday that the government had made a mistake at the time. He said: “We should have opposed it,” although he added that he would not have complied even if the vote had been lost.
The government’s chief lawyer sought to sell the Brexit deal to MPs on the grounds that it represented “a calculated risk”.
He was asked by Joanna Cherry of the SNP if there was anything to prevent the Northern Ireland backstop, under which the UK would remain in a customs union with the EU after Brexit, becoming permanent.
Cox replied: “As a matter of international law, no,” but added that if the backstop did become permanent, it would be “highly vulnerable to legal challenge” within EU law.
Downing Street had hoped to start persuading backbenchers to support May’s deal despite widespread concern in her party that the UK could become trapped in the backstop. May spoke with small groups of backbench MPs in her Commons office throughout the day.
On Tuesday, the prime minister will openthe five-day debate leading up to the final vote next week by saying that the British people have already twice voted to deliver Brexit.
The prime minister will argue that the British public showed what they wanted “by voting overwhelmingly for parties that committed to delivering Brexit” in the referendum and in the 2017 election Both Conservative and Labour manifestos at the last election said they respected the leave vote in the 2016 referendum.
Tuesday’s debate will be closed by the Brexit secretary, Stephen Barclay, and the following days will be themed, with senior cabinet ministers speaking in support of the deal.
Wednesday’s theme will be security and the debate will be opened by the home secretary, Sajid Javid, and closed by Jeremy Hunt, the foreign secretary. On Thursday, the focus will be on the economy, opened by the chancellor, Philip Hammond, and closed by the international trade secretary, Liam Fox.
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