The government is shutting down public debate by refusing to allow legal opponents to reveal the official justification for using royal prerogative powers, rather than seeking parliament’s approval, to trigger Brexit, according to documents lodged in the high court.

A submission lodged in the court on Friday contains redacted sections where significant paragraphs are blacked out.

The submission is a final “skeleton argument” from London law firm Bindmans on behalf of people challenging the government’s decision to trigger article 50 without consulting parliament.



Claimants of the People’s Challenge, a crowdfunded initiative, comprise those living in the UK, Britons resident on the continent and citizens of Gibraltar.

The preliminary legal skirmish comes ahead of next month’s test case over whether parliament – rather than the prime minister – has the power to notify Brussels, under article 50 of the Treaty on European Union, of Britain’s intention to leave the European Union.

The government is refusing to allow its legal opponents to reveal its explanation of why it ought to be able to use royal prerogative powers to trigger article 50.

In an attempt to open up debate about parliament’s authority before the hearing begins on 13 October, the claimants’ lawyers have submitted an urgent challenge alleging that the government is over-exploiting a commitment to protect litigants from online abuse to prevent disclosure of the main points of its defence.

When the identities of some of those launching the legal challenge became known earlier this summer, they were subjected to abuse and threats on social media. There were also protests by Brexit supporters outside lawyers’ offices.

The four-page submission, drafted by Helen Mountfield QC, John Halford, a solicitor partner at Bindmans, and other lawyers, says they wish to publish their own unredacted skeleton argument and that of David Davis, the Brexit secretary, when it is served on the court and parties to the case.

It maintains that: “Publication of [such] documents … would not create or increase any risk of abuse towards the parties, and withholding publication serves no protective end.” Previous court orders, it adds, “were not intended to prohibit disclosure of documents that would normally be available to the public”.

It continues: “All parties agree that the issue at the heart of this case is of the utmost public interest. The government has indicated publicly that it believes its position on the issue to be clear and is confident in the legal arguments that underpin it. Statements by ministers have already informed the public that the government’s position is that article 50 can be triggered through use of the royal prerogative without an act of parliament. Members of the public ought to be able to see how those arguments are set out.”

Halford told the Guardian: “The People’s Challenge group had planned to publish the government’s written defence alongside their own written submissions to the court, enabling the nation to see and engage with the competing arguments.

“Remarkably, the government is insisting that every word of its defence must be kept confidential. An urgent application has been made to the court to challenge its stance. The prime minister’s reasons for believing that she alone is empowered to take Britain out of the EU cannot be treated as a state secret. The extraordinary stakes in this case mean that justice must be as open as possible.”

A government spokesperson said that keeping the document secret was a decision taken by the courts: “This is not a decision that has been taken by the government. The court has considered it appropriate to put in place a confidentiality order for reasons including the threats received by some claimants. It is important that this court order is adhered to.”

Article 50 of the Treaty on European Union says that any state may withdraw from the EU “in accordance with its own constitutional arrangements”, but does not specify what those arrangements should be. The prime minister says it is up to her to give notice; the claimants argue that parliament’s approval is required.

The redacted version of the skeleton argument submitted by the People’s Challenge invites the court “to declare that the UK’s constitutional arrangements mean that only parliament can lawfully ‘decide’ to leave the EU for the purposes of article 50 TEU; and that [David Davis] may only ‘notify’ such a decision to the European Council under Article 50(2) TEU once he has been properly authorised to do so by an act of parliament.”

It also quotes approvingly from the 1689 Bill of Rights – a piece of legislation revered by Eurosceptics – that it “expressly prohibits the use of the prerogative in circumstances where its exercise would ‘suspend’ or ‘dispense’ statutory law.”

Among those backing the People’s Challenge claim are Grahame Pigney, who lives in France; Paul Cartwright, a Gibraltarian national who runs the campaign Brex-IN; Christopher Formaggia, who lives in Wales; and Tahmid Chowdhury, a London student.



They maintain that Brexit will take away many of their rights. “In Gibraltar, 96% of us voted to remain,” Cartwright said. “We have had a booming economy until now. We have freedom of movement, although Spain is already giving us so much trouble. They say that once we leave they will take joint sovereignty. My wife has friends in Spain and goes across the border almost every day. I don’t know what will happen once we leave.”

Pigney said: “The rights and privileges of Britons didn’t figure in the Brexit debate. The referendum was advisory. It must go back to parliament.”