Last week saw the English and Scottish courts deliver conflicting judgments on whether the prime minister’s advice to the monarch, which led to the prorogation (i.e. suspension) of parliament, was unlawful. This explainer sets out the issues which the Supreme Court will have to deal with on Tuesday 17 September.
Prorogation is the means through which parliament brings a parliamentary session to an end. Except for those provisions that can carry over, legislation in the pipeline comes to an end.
A new Queen’s speech is prepared setting out the government’s new legislative agenda for the next parliamentary session. Most modern prorogations have been for much shorter time periods than the current one.
The issue before the courts is whether this prorogation was for an improper purpose.
Was it designed to stymie political debate, allowing the government to achieve its policy goal of leaving the EU on 31 October? Or was it designed to bring an overly long parliamentary session to an end, allowing a new prime minister to set out his legislative agenda?
The Inner House of the Scottish Court of Session, the highest court in Scotland, concluded both that it could review the advice to prorogue parliament and that the advice was unlawful.
The purpose of prorogation, according to the court, had not been to enable the prime minister to launch a legislative agenda via a Queen’s Speech, but to stymie parliament and prevent it from holding the government to account for its Brexit policies.
The English courts disagreed. According to them, prorogation was political, not legal. There were no legal standards, they said, through which the court could assess the prime minister’s advice to the monarch to prorogue parliament.
The Supreme Court will decide the case by looking at the law. But it is impossible to avoid the fact that the decision will have significant political repercussions.
However, its constitutional implications will be larger still. This is because the judgment is about how the government is held to account for its actions.
When should the government be accountable to parliament and when should it be accountable to the courts? Should parliament or the courts step in when the other institution is unable to hold the government to account?
It is hard to deny that prorogation raises political issues. How long parliament is prorogued, and why, are questions of politics. To allow the courts to dictate the length and purpose of prorogation would be for the courts to intrude on a matter of politics.
This led the English High Court to conclude that there were no legal standards against which to assess the prime minister’s advice to the monarch. How long is too long? How are we supposed to discern the prime minister’s motives?
Yet whilst prorogation does involve issues of politics, it is also an executive power. The government advises the Queen to issue an Order in Council to prorogue parliament. Like all executive powers, it is subject to legal limits. No limits would risk undermining the rule of law.
In the Scottish case, Lord Drummond Young argued that prorogation is the same as any other prerogative power. All prerogative powers are subject to legal controls.
Hence, if the court concludes that the prime minister advised the monarch to grant prorogation for the wrong purpose, this is a legal error that the court can correct.
This judicial scrutiny can then lead to greater political scrutiny. Parliament could be recalled, facilitating political scrutiny over prorogation as well as Brexit.
Alternatively, it is important to recognise the specific nature of the challenge made in both of these cases. Are there clear legal and constitutional limits on prorogation? Should these limits be stronger when faced with an unprecedented situation?
As the Yellowhammer document reveals, a no deal Brexit could have serious legal, social, political and constitutional consequences. These need to be debated in full. Parliament should hold the government to account for its actions.
But, how can it do so if it is prorogued, leaving little, if any time, for the normal political means of accountability to apply?
The court is also required to uphold the UK’s (uncodified) constitution, drawing on legislation and principles of the common law. The UK constitution is based on parliamentary sovereignty, the separation of powers and the rule of law.
Prorogation harms parliamentary sovereignty, as it prevents parliament from holding the government to account, and from ensuring that the government remains in power only, and to the extent that, it enjoys the confidence of the House of Commons.
In a similar way, prorogation undermines the separation of powers. Stymying the will of parliament potentially reverses the separation of powers. It could allow the executive to thwart the will of the Commons, rather than being held to account by the Commons for its actions.
Prorogation could undermine the rule of law if it enables the government to prorogue parliament with no legal restraint on its actions at all.
To say that prorogation can never be reviewed by the courts is essentially to argue that any prime minister could prorogue parliament to such an extent that parliament only meets to approve the budget (the Bill of Rights 1688 preventing the executive from levying money through prerogative powers), or that prorogation could occur whenever the government faced a potential defeat in the Commons.
In other words, it would provide the green light for parliament to sit only when it suits the executive.
Whatever the Supreme Court decides, it is its job to look at the law and the principles of the UK constitution. To wade too far into politics could potentially undermine the independence of the judiciary.
Could the judges be accused, rightly or wrongly, of deciding the case according to their own views on Brexit? But to fail to uphold the principles of the UK constitution undermines the rule of law.
There is no easy answer to these deep-rooted questions. The Supreme Court will look at the legal arguments presented to it, evaluate them against past case law, and ignore the political backdrop.
If the first Miller case demonstrated anything, it is that, despite some media criticism, the Supreme Court can be trusted to do its job impartially, looking to the law whilst being mindful of the constitutional limits on its own powers.
By Alison Young, Professor of Public Law at the University of Cambridge, and Catherine Barnard, senior fellow at the UK in a Changing Europe and Professor of EU Law and Employment Law at the University of Cambridge.