Parliament is the master of its own proceedings

The argument

The argument rests on where the authority to decide parliamentary business lies. Prorogation is an established part of how Parliament operates: sessions end and new ones begin, and the timing of that has long been a matter for the government of the day. Boris Johnson was Prime Minister and the leader of the majority party, which placed the decision squarely within the ordinary exercise of the office. Proponents of this position argue that using a recognised power in a recognised way does not become unlawful because the circumstances in which it was used were contested. The deeper claim is that Parliament is the master of its own proceedings. When it sits, and for how long, is an internal matter for the institution and the government drawn from it, settled by the conventions and arrangements it has developed for itself. The principle is of long standing precisely because the alternative — an outside body ruling on the timetable of the legislature — raises difficulties of its own about where authority over Parliament ultimately rests. What the position does not claim is that the decision was beyond challenge. It holds that the challenge belongs in politics rather than in law. If the public does not like it, the remedy available is the ordinary one: MPs and the Prime Minister can be held to account by an expression of displeasure at the ballot box, and a government that misjudges what the electorate will tolerate pays for it there. That is how decisions of political judgment are supposed to be reviewed. On this reasoning the two questions must be kept apart. Whether the move was wise, or proper, or well-motivated is a matter on which people may disagree and on which voters may deliver a verdict. Whether it was legal is the narrower question, and because the power was the Prime Minister's to exercise and the sitting timetable Parliament's own affair, the answer given is that it was.

Context

It is up to Parliament to decide when it sits and when it is prorogued. As the Prime Minister and head of the party with the most parliamentary seats, Boris Johnson was within his legal rights to prorogue parliament.

Premises

Counter-arguments

Where does it end? If we accept that the prime minister has the power to determine when the parliament, what is to stop a prime minister from proroguing parliament for weeks, months, or even years at a time? The prime minister does not have unlimited legal authority to prorogue parliament indefinitely. They are constrained by legal precedents and the constitution. There is no legal precedent for the prorogation of parliament for 33 days. Nor is Johnson permitted, within the constitution, to prorogue parliament for the purpose of stymying debate and bypassing the democratic process.

Rejecting the premises

[Rejecting P2] But Boris Johnson is bound by the constitution and legal precedents. [Rejecting P3] His prorogation was a break with convention and in breach of the constitution.