Until indications emerged this morning that Boris Johnson accepted what everyone else had known for some time — namely, that his position as leader of the Conservative Party and Prime Minister had become untenable — there was a good deal of talk about a ‘constitutional crisis’. But was there really such a crisis? And, relatedly, was it fair to suggest that the relevant rules were unclear or that matters would have been better dealt with under a written constitution? I’m not sure it was.

Even if their application may raise some occasionally tricky practical questions, and even if they are found in sources, such as the Cabinet Manual, that might seem odd to those who are more familiar or comfortable with written constitutional systems, the relevant constitutional principles are reasonably straightforward and clear. The core principle is that the Prime Minister’s authority is a function of their leadership of a political party (or, exceptionally, their position at the helm of a coalition of parties) that enables them to command the confidence of the House of Commons. The application of that principle is normally entirely straightforward, such that the person who is leader of the party with an overall majority can be taken to enjoy the support of their own MPs and hence to be in a position to command the confidence of the House of Commons.

Of course, things become less straightforward when, as has happened this week, the relationship between the leader of the governing party and their own MPs breaks down. By the middle of the week, it had become clear — albeit that it had not been confirmed by way of a formal vote — that Boris Johnson had lost the confidence of the majority of Conservative MPs. Since he could also be presumed not to enjoy the confidence MPs from other political parties, it could readily be inferred that he was no longer in a position to command the confidence of the House of Commons as a whole. In those circumstances, it is incumbent on a Prime Minister to resign. There is, of course, an evidential question that might need to be addressed if — as appeared for some time to be the case with Johnson — a Prime Minister is reluctant to recognise facts. The most straightforward way of addressing that question is for the Prime Minister’s own party to confirm, by way of a confidence vote, that it no longer has confidence in him. It seems clear that the Conservative Party would have held such a vote next week had Johnson failed to read the writing on the wall today.

What would have happened if Johnson had refused to announce his resignation as leader of the Conservative Party, either with or without the Party having held a formal no-confidence vote? Another way of putting the question is to ask: is the country beholden to the Prime Minister’s whim and/or the willingness or capacity of their party to hold a no-confidence vote? The clear answer is ‘no’. It is always open to Parliament itself — as distinct from the Prime Minister’s political party — to vote that it has no confidence in the Prime Minister. If such a vote is held, formally demonstrating that the Prime Minister no longer has the confidence of the House of Commons, the Prime Minister is constitutionally required to resign. If he or she refuses to do so, the Monarch is constitutionally permitted — and required — to dismiss the Prime Minister. At that point, the Monarch can appoint as the new Prime Minister the person best-placed to command the confidence of the House of Commons. If it is not possible to appoint as Prime Minister someone capable of leading a Government that will enjoy the confidence of the House of Commons, Parliament should be dissolved and a general election held.

There is nothing inherently improper in Johnson remaining as Prime Minister until his successor is identified — indeed, that would be the norm. But there is a concern — against the background of the ethical and other concerns that precipitated his downfall — that Johnson may remain as Prime Minister until October, if it takes the Conservative Party that long to elect a new leader. Can he do that? This, too, is ultimately within Parliament’s control. If the Conservative Party is incapable of running an election process according to a timetable that Parliament finds acceptable, it is open to Parliament to hold a vote of no confidence, at which point, as described above, the Prime Minister will be constitutionally required to resign, failing which he must be dismissed. Indeed, the leader of the Labour Party, Keir Starmer, has announced that if Johnson seeks to stay on as Prime Minister for a significant interim period, a parliamentary vote of no confidence will be held.

Would Conservative MPs vote ‘no confidence’ in such circumstances? That would be up to them — but they cannot have it both ways. If sufficient of them were unwilling to do so, the no-confidence motion would fail to carry, Johnson would be able to claim the ongoing confidence of the Commons, and he would constitutionally entitled to remain as Prime Minister pending the outcome of the Conservative leadership election process. Such an outcome would not be evidence of the constitution ‘not working’: rather, it would be evidence of what some might consider the relevant Conservative MPs’ spinelessness. This approach would stand the best chance of ‘success’ — if the objective is to remove Johnson and install an interim Prime Minister — if, prior to the vote of no confidence being held, a clear understanding had emerged, eg via the Cabinet, as to who should serve in place of Johnson pending the conclusion of the Conservative leadership election process. That would avoid the risk a vote of no confidence in circumstances where it was not readily possible for the Monarch to appoint a temporary replacement, which in turn would risk the need to dissolve Parliament and hold a general election. It is therefore wrong to suggest that Johnson cannot be removed as Prime Minister — he can, consistently with the overriding constitutional principle that any Prime Minister must retain the confidence of the House of Commons. This does not mean that removing a Prime Minister is easy, but that is a feature, not a bug.

So has the constitution ‘worked’? That depends on what we expected of it. However, based on the established understanding of how Government works and is sustained in the UK, it is difficult to see in what sense the constitution has failed to work. Within a day or two of it becoming clear that the Prime Minister had lost the confidence of most of his own MPs — and only a few short weeks after Conservative MPs expressed confidence in Johnson through a formal party vote — he announced his intention to resign as leader of his party, thereby setting in train a process that must result in his resignation in due course as Prime Minister. Had he failed to do so, it would have been open to the House of Commons, by way of a formal no-confidence vote, to oust him. Equally, if it turns out that the Prime Minister may stay on for a period that is considered unacceptably lengthy pending the conclusion of the Tory leadership election process, it will be open to the House of Commons — provided that sufficient Conservative MPs are willing to support such an approach — to oust him via a no-confidence vote. Would a written constitution have made any difference? That depends on what the terms of a written constitution might be. If the UK were to adopt a written constitution, it might take the opportunity to adopt an entirely different system for determining matters concerning the appointment and departure of Prime Ministers. In that case, a written constitution would, of course, operate differently from current arrangements. But if we were simply to codify existing arrangements by putting them into a written constitution, there would have been no substantive difference. It might, of course, have made the rules clearer — and I do not underestimate the importance of that. But in my view it is inaccurate to suggest that a written constitution would necessarily have dealt with this week’s extraordinary political events differently, better or more efficiently than the existing constitution, at least if the goal is to ensure fidelity to the cardinal principle that the Prime Minister can govern only when he or she enjoys the confidence of the House of Commons.