The government has been forced by a senior judge to reveal secret legal arguments for refusing to let parliament decide when and how the UK should withdraw from the European Union.
In a preliminary victory for those challenging Theresa May’s power to trigger Brexit, a high court judge, Mr Justice Cranston, has swept aside restrictions on publishing official documents before the hearing on 13 October.
In the released documents, lawyers for the government argue that it is “constitutionally impermissible” for parliament to be given the authority rather than the prime minister and dismiss any notion that the devolved nations – Scotland, Northern Ireland and Wales – will have any say in the process.
They add: “The appropriate point at which the UK should begin the procedure required by article 50 [of the European Union treaty] to give effect to [notifying the UK’s exit] is a matter of high, if not the highest policy.
“[It is] a polycentric decision based upon a multitude of domestic and foreign policy and political concerns for which the expertise of ministers and their officials are particularly well-suited and the courts ill-suited.”
The government submission states: “The lawfulness of the use of [royal] prerogative is not impacted by the devolution legislation. The conduct of foreign affairs is a reserved matter such that the devolved legislatures do not have competence over it.”
The government had refused to allow its legal opponents to reveal before the case its explanation of why it ought to be able to use royal prerogative powers to trigger article 50.
But in an order handed down by Cranston on Tuesday, he told both parties: “Against the background of the principle of open justice, it is difficult to see a justification for restricting publication of documents which are generally available under [court] rules.”
Cranston’s decision has also allowed the People’s Challenge, a crowdfunded group, to publish its full claim without any sections of it being redacted or withheld. It argues that “only parliament can lawfully ‘decide’ to leave the EU for the purposes of article 50[of the treaty]; and that the [government] may only ‘notify’ such a decision to the European council under article 50(2) once [it] has been properly authorised to do so by an act of parliament”.
Responding to the release of the skeleton arguments, John Halford, a solicitor partner at Bindmans law firm, which represents the People’s Challenge, said: “The court’s order allows a floodlight to be shone on the government’s secret reasons for believing it alone can bring about Brexit without any meaningful parliamentary scrutiny.
“Those who were unsettled by the government’s insistence on its defence being kept secret will now be surprised by the contents, including submissions that Brexit has nothing constitutionally to do with the Scottish and Northern Ireland devolved governments, that parliament ‘clearly understood’ it was surrendering any role it might have in Brexit by passing the EU Referendum Act, that it has no control over making and withdrawal from treaties and that individuals can have fundamental rights conferred by acts of parliament stripped away if and when the executive withdraws from the treaties on which they are based.
“These arguments will be tested in court next month, but now they can be debated by the public too.”
The attorney general, Jeremy Wright QC will lead the government’s case in court on 13 October. He will appear alongside James Eadie QC and Jason Coppel QC.
Wright said: “The country voted to leave the European Union, in a referendum approved by act of parliament. There must be no attempts to remain inside the EU, no attempts to rejoin it through the back door and no second referendum. We do not believe this case has legal merit. The result of the referendum should be respected and the government intends to do just that.”
He will appear at the hearings in the high court on 13 and 17 October.
