Bad enough for a prime minister unlawfully to suspend parliament at a moment of acute national crisis. But now a series of attacks, including from the prime minister’s office and the Lord President of the Privy Council, on the rule of law.

These are already extraordinary times. And who of us can say with confidence that we will not see worse? The last few years represent a never-ending succession of constitutional “hold my beer” moments.

How do we stem—or even reverse—the damage our constitution is sustaining? Yesterday’s Supreme Court decision is what it is, but a prime minister willing to shrug off the political cost of legal defeats can continue to suspend parliament at will and ministers have refused to rule out doing so.

How can MPs scrutinise when the scrutiny can be ended if ever it becomes uncomfortable? And how can MPs legislate to remove the power to prorogue from the prime minister if he can defeat that legislation by, yes, suspending parliament?

The unadorned truth is that, if MPs are to fulfil their democratic obligations, there is no alternative to replacing the prime minister. MPs know this—but what has held them back is what they perceive to be the risks.

Labour’s position is that Jeremy Corbyn, as leader of the Opposition, must have the first attempt at replacing Boris Johnson. But if, because of a lack of cross-party support, he failed, what then? In that world Labour might contemplate an alternative, but, if none could be found within 14 days the Fixed-term Parliaments Act 2011 (FTPA) would trigger a general election and the dissolution of parliament at a very inconvenient moment.

That, at least, has been the thinking. That is the risk that has held MPs back from making the attempt. But is it right?

Legal advice from a leading constitutional law QC, Helen Mountfield, tells us that a vote under the FTPA is not a necessary precondition to the replacement of the existing prime minister with another. There are other mechanisms for his replacement that do not carry with them the risk of a dissolution.

The advice reads: “The House of Commons has more than one mechanism available to it by which it could identify an individual in whom it had confidence and communicate that view to the Queen… Those mechanisms are available, both when parliament is in session, by means of a humble address, and when it is not.

“If a majority of members of the House of Commons were to clearly identify an individual in whom the House has confidence, the Queen would invite that individual to form a new government.” The process “is governed by convention and those conventions will apply equally whether or not parliament has passed a no confidence vote in the government, pursuant to s. 2 FTPA.”

The consequence is that MPs could have, in effect, a free hit at replacing Johnson. Or even two free hits—first, asking whether there might be a majority for Corbyn and, if not, second, whether there might be a majority for someone else. And if there has been no vote of no confidence under the FTPA then there is no risk of a general election if MPs cannot cohere around an alternative.

Ah, but who? Well, that would depend on what the prime minister was for, and for how long.

The attacks from No 10 on the supremacy of parliament and the rule of law are not the disease—they are merely symptoms of what has ailed us since 2016. And the first task of an emergency government would be to tackle it.

Successive governments, and prime ministers, have made no attempt to find in the referendum vote a democratically sustainable mandate for anything. They have conspicuously failed to engage the public in the compromises it requires. We have had instead a series of grand but undeliverable promises. These have outraged alike Remainers and Leavers, the former sniffing further deceit and the latter further betrayal.

These tensions would not be resolved by the mechanical logic of a further referendum—instead they would be exacerbated. First we need a national conversation that engages the electorate in the choices before us. The first act of an emergency government should be to commission a statutory inquiry under the 2005 Inquiries Act. It would appoint a panel of independent members to listen to the evidence and get to the truth. If we leave the EU what relationship does the electorate want with it? What advantages and disadvantages would such a relationship bring? Would such a relationship be acceptable to the EU? And might it have a majority in the country?

For four months they could hear evidence from the public, from pollsters and trade experts and economists and lawyers and then produce a report. Collectively we could engage with those questions. And if the answer was, as I hope it would be, that there was such a model, it should be put back to the electorate in a referendum.

And, on the domestic front, while that Inquiry investigated and reported, the emergency government could implement a non-partisan programme of constitutional reform. Perhaps the only thing we have learned for sure from the last three years is how badly we spent the previous 300. Our common law constitution was not, as we told ourselves, flexible and muscular. It was just untested and, now it has been, it can be seen to be not fit for purpose.

We need to reform parliamentary procedure—including that governing the suspension of parliament without its consent. We need to rethink our electoral laws which—as matters stand—meaningfully penalise only the compliant. We should revisit the FTPA. We must take up Lord Hennessy’s idea of a constitutional convention.

An emergency government that spent six months pursuing a programme of constitutional reform at home and working to cure our Brexit-ills with a public conversation might be something around which MPs could cohere. It might take the heat out of our politics—and arrest an alarming national decline.

And there is no reason not to try. Because that which MPs have feared—a general election—they need not.