Attempts to trivialise Article 50 litigation are unworthy.

The lord chief justice is about to hear what some have described as this generation’s most important constitutional case. Others, including the prime minister, dismiss it as forestalling Brexit’s inevitability. Who is right?

The litigation began inauspiciously when Spanish hairdresser Dier Dos Santos issued an urgent judicial review of the decision the government had then yet to make about precisely how to exit the EU. It was taken seriously though, and listed for a directions hearing on 19 July before the QBD’s president.

By then the government’s legal colours were pinned to the mast – there would be no act of parliament authorising Brexit. Instead, Theresa May would use the royal prerogative to give effect to the referendum result. Since then she has indicated there will not even be a parliamentary vote.

Meanwhile, other legal claims were threatened by Mishcon de Reya clients and grassroots campaigners ‘The People’s Challenge’ instructing Bindmans. They were invited to the directions hearing by the court. It emerged that the Mishcons’ claim was to be courageously headed by investment manager Gina Miller and hers was designated as the lead case, though the court accepted that others needed to be heard.

Pleadings are now being exchanged, but there has been fierce debate about the appropriateness of the litigation. During last week’s prime minister’s questions, May told the house the government had a ‘clear’ position on invoking Article 50 – ‘this is a prerogative power’ – and as regards the litigation: ‘No one should be in any doubt that those who are trying to prolong the process by their legal references in relation to parliament are not those who want to see us successfully leave the European Union; they are those who want to try to stop us leaving.’

A good soundbite perhaps, but one that needs unpacking.

First, it implies that the prerogative is a tool, neatly labelled ‘For Use in the Event of Brexit’. Constitutionally, that is quite wrong. The prerogative is simply the exercise of the monarch’s vestigial powers by the government of the day. It can only be used when parliament has not already decided it is too blunt for use by a single minister in a particular context, as happened repeatedly over the last four decades in relation to EU membership. That has led parliament to grant enhanced citizenship rights to British citizens living here and abroad which are also woven into the constitutional settlement of the UK, including with the people of Northern Ireland and Scotland and its territories overseas. What parliament gives, no single minister can take away. Only an act will do.

The complaint that all of this is legal sophistry intended to ‘prolong the process’ is also misplaced. At the July hearing, May’s barrister confirmed she would not invoke Article 50 until 2017. All agreed that the case should be concluded speedily so she could have guidance before then from the Divisional Court and, if necessary, the Supreme Court. Diaries were cleared and expedition directed. Hardly stalling tactics.

Nor is the court asked to block Brexit, only to make a declaration confirming that the responsibility for it falls to all members of parliament rather than one alone. Parliament will then decide what becomes of individuals’ rights, what Brexit really means for businesses, and if there may be an alternative. None of that would be lawyer-driven, but it would be democratic.

Last, the government’s position has been less than ‘clear’. Before the referendum, the British public were not told that there would be no parliamentary control over what would follow. As with Brexit generally, no plans were made.

The point of the Article 50 litigation is to secure the legal certainty, and in turn the parliamentary scrutiny, that something as serious as the stripping away of citizenship rights from 65 million people so obviously demands. Attempts to trivialise the case are unworthy.

John Halford is a solicitor at Bindmans acting for the People’s Challenge group