John Major has threatened personally to bring legal action if the next prime minister were to attempt to prorogue Parliament in the autumn. On Tuesday, Dominic Grieve MP moved an amendment that might encourage legal challenge to an attempt to prorogue. It is unclear whether John Major sought to rely on the Grieve amendment or instead made his case on wider grounds, in line with a recent argument that the courts would block prorogation. It might well be politically unwise to prorogue Parliament in the autumn, making a bad situation worse. It may be difficult to imagine situations in which it would be a helpful contribution to securing UK exit from the EU. We take no view on those questions. But it would be extraordinary if the courts were to quash a prime minister’s recommendation to prorogue Parliament on legal grounds. 

Like the prerogatives to dissolve Parliament (which the Fixed-term Parliaments Act 2011 swept away) and to appoint or dismiss ministers, this is a constitutional prerogative in relation to which one would never previously have expected judicial intervention. It is a very bad idea to invite or encourage judicial intervention in this context.

John Major does not specify the grounds on which the courts would be asked to act, but takes for granted that they would be intervening to prevent a constitutional outrage.

But it is important to remember that not every unconstitutional action gives rise to a legal remedy. The Supreme Court rightly recognised this in the Miller Article 50 judgment in refusing to consider whether the Sewel Convention applied to legislation for terminating the UK’s membership of the EU. 

A government, which enjoys the confidence of the House of Commons, is entitled to determine when the current session of parliament is ended by a prorogation. It may be unwise or imprudent to do so in circumstances that give rise to political controversy, but it would require more than just that to amount to an unconstitutional attempt to govern without parliamentary support. 

Much of the discussion about prorogation, including John Major’s recent intervention, has failed to attend carefully to important distinctions between different contexts in which it might take place ( these distinctions are set out in a helpful paper by the House of Commons Library (11 June 2019, No. 8589).

Proroguing Parliament to avoid a vote of no confidence being moved and lost would be impossible, in current circumstances, to justify as constitutional.  Still, in rather different circumstances, even that was accepted, though highly controversial, in Canada. 

If the House of Commons knows that the government is proposing to prorogue, and forgoes the opportunity to defeat the government on a vote of no confidence, any objection to the prorogation must be weaker. Likewise, if a cross-party coalition of MPs were to attempt to legislate against the wishes of the government in reliance on departures, sanctioned by the Speaker, from normal rules and procedures, and as an alternative to pushing matters to a vote of no confidence, then prorogation might also then be seen as politically justifiable.    

We take no view on whether it would be right for the next prime minister to prorogue Parliament in the autumn. The question for the government will be whether they think there is a legitimate political justification for a prorogation and are willing to accept responsibility for that in a subsequent general election. The question for the Commons would be whether it is willing to support a government that is proposing to prorogue. None of this is for the courts to decide.

Before the Fixed-term Parliaments Act 2011, the prime minister could clearly seek and be granted a dissolution of Parliament. There has been much criticism of that Act. In the absence of the Act, a dissolution would have provided another obvious and legally unimpeachable means to prevent the House of Commons from attempting to legislate to compel the government to delay or cancel withdrawal. 

In the past, it would have been regarded as a wholly rational approach to a failure by the House of Commons to accept a major policy of the government. The logic has not changed. Dissolution would put the government and the Commons more generally to the judgment of the electorate. A prorogation leading to a general election would be consistent with constitutional principle and would not be inconsistent with anything in the 2011 Act.

Inviting the courts to intervene to prevent a prorogation would be to call them in aid to prolong the period during which parliamentarians would have the opportunity to change the legal default (no-deal exit on 31 October), whether by withdrawing confidence and transferring it to an administration willing to apply for an extension or by legislating to require the government to apply for an extension.  Litigation to challenge prorogation would embroil the courts in a political controversy of a sort that they have no function or qualification to resolve. 

The traditional grounds of judicial review would not justify an intervention. There is no legal principle that entitles the House of Commons to unlimited time to undo its previous decisions. However, the courts might feel some pressure to act, not least because of the polemical narrative, to which John Major’s remarks contribute: that prorogation would be a return to Stuart-era abuses. That narrative is unconvincing; it is also legally irrelevant.

There has been an argument put forward that proroguing Parliament would flout parliamentary sovereignty. However, parliamentary sovereignty means that whatever the Queen in Parliament enacts is law. It does not mean that there must always be time for the House of Commons to attempt to change course.

Whatever political prudence may require, it is misconceived to think that parliamentary sovereignty requires the House of Commons to retain the capacity, right up until 10.59pm on 31 October, to insist on the abandonment of a process already enshrined in statute. 

The House of Commons is always entitled to withdraw confidence in the government. If it wants this withdrawal to be in good time to make it possible for an election to be held and a new government returned that might support an extension (or even revocation) of Article 50, then it should act sooner rather than later. It would be wrong for the government to prorogue Parliament in order to avoid defeat in a vote of no confidence, but, even for that, the remedy is political not legal action. And in other contexts, such as those noted above and in the House of Commons Library note, the political merits and constitutional legitimacy of prorogation would be more contestable.

How does Tuesday’s amendment to the Northern Ireland (Executive Formation) Bill change this analysis? In an article published on Monday, before the text was fully known, we argued that a statutory duty to report to the House would not be enough to displace the prerogative.

One of Dominic Grieve’s other amendments (modelled on the Civil Contingencies Act) made provision for Parliament’s recall even if prorogued. But this amendment was not selected. Our analysis still holds: the amendment that has been adopted is insufficient to make prorogation in the autumn unlawful and if it were sufficient, it would have required Queen’s Consent (different from royal assent) in the Commons, and will require it in the Lords next week.

The significance of Dominic Grieve’s amendment may be more that it encourages litigation; it may already have encouraged John Major to threaten litigation.

Independent courts should not be swayed by the temper of the times and should refuse to quash any advice to prorogue. It is irresponsible to expect the courts to intervene in matters that are highly political and over which they have no clear jurisdiction. Such intervention would be bad for the constitution and for the courts.