The UK is showing enormous trust in the resilience of its democratic culture. Is it right to?

It is not normally a symptom of healthy democracy when the government demands that citizens stay confined in their homes and parliament rubber-stamps it into law, then disbands for weeks. But these are not normal times.

The extreme measures required to contain the spread of coronavirus require suspension of many habits of a free society, including the right to move around the country and assemble. Removed from the context of a deadly virus the political shift looks wildly authoritarian.

The lack of censorship indicates that something more consensual is going on. There is no need to repress dissenting voices because no one is siding with the disease. Even recalcitrant libertarians who pull at the leash of “social distancing” recognise the need for some restraint. The relative ease with which Britain has accepted the requirement that civil society be banished from public space expresses underlying confidence in some deep cultural inoculation against tyranny. There are historical grounds for that faith, but it easily shades into complacency. The UK is not going to slide into despotism in response to public health emergency, but there are many modes of liberty between the freedoms we enjoyed before coronavirus and the limitations now imposed to contain it. How can we be so sure, once the crisis has passed, that we will naturally revert to our starting point on that spectrum?

A truly authoritarian government would not have written automatic expiration dates into its draconian law. Boris Johnson has many character flaws but he has not given the impression of a man itching to use Covid-19 as the pretext for a vast executive power grab.

He looks more vulnerable to the opposite charge: negligence stemming from aversion to anything that smacks of intrusive government. There is no ideology coherent enough to be called “Johnsonism” but the prime minister's messy creed borrows equally from Thatcherite suspicion of the “nanny state” and from a belief—more libertine than liberal—that people should be allowed to indulge themselves. Johnson went into this crisis with a predisposition not to close pubs. He also recognises that a capitalist economy relies on high turnover of individual freedoms expressed as private-sector transactions.

There will always be a section of the polemicist left that wants to accuse Tory leaders of fascism, but here we have an incidence of a Conservative prime minister conspicuously uncomfortable with the application of near totalitarian power. It is possible that the experience of having contracted the virus himself will shape his subsequent thinking; we will know soon enough. Whatever the motive behind Johnson's initial reluctance to pull hard on the levers of state control, it seems to reflect some resilience in our democratic culture. That is reassuring because the health of British democracy relies on habit as much, or more than it resides in law.

It is not true to say that our constitution is unwritten. It is just not written down in one place. It is contained in an edifice of accrued statutes, given some semblance of shape by convention and ritual.

Last September, when Johnson prorogued parliament in an attempt to remove an obstruction from the path to Brexit, outraged Remainers condemned it as the act of a dictator. Some Eurosceptics were squeamish, but more complained about judicial activism when the Supreme Court ruled that the prime minister had acted unlawfully. It seemed that a vulnerability had been exposed in the operating system of British democracy. The belief that royal prerogative powers should not be wielded for partisan ends turned out to not be worth much if the occupant of Downing Street does not himself believe in it.

That episode contains the pinch of salt to take with any admiration for Johnson's displays of liberalism. But he did yield to the Supreme Court. What threatened to be an unravelling of the rule of law ended with a reassertion of its primacy. The prime minister could not get Brexit done by dissolving an obstructive legislature, and got it done instead by winning an election, which is obviously better for democracy (albeit a measly compensation for Remainers).

It is not naïve to think that British democracy is secure enough to withstand a small dose of authoritarian-style government. The comparison with wartime is imprecise but apt enough. The current restrictions also stop short of what has been done in the past when there was a military foe at hand. There is no fear of a pro-virus fifth column needing internment.

But a strong sense of collective endeavour can itself breed complacency about the threat to democratic norms posed by emergency measures. The clinical rationale behind the requirement for lockdown strips away political controversy, and the logic of social distancing makes it impractical for most Westminster business to be conducted as before. The Commons chamber, usually densely packed with bodies, had to be thinned out for the debate on emergency measures. There was no agreement before parliament went into recess on how the government might be held to account if MPs are unable to gather in one place. Press conferences are now conducted by video link.

No one disputes the necessity of the changes, but there is something unnerving about this casual acceptance of a cordon sanitaire between those who wield power and those whose job it is to keep the powerful in check. Democratic scrutiny is now happening remotely, and the remote control is in Downing Street hands.

Britain, along with other democratic countries dealing with the pandemic, is conducting a vast experiment in trust. There are legal guarantees that extreme measures will expire, but also provisions for their renewal. We can reasonably presume that the current government has no interest in retaining the apparatus of a police state for longer than necessary, but even the most reasonable presumption falls short of a constitutional guarantee.

Temporary legal changes leave cultural tide marks. The longer the suspension of civil norms, the more their absence becomes a new normal. The fact that Johnson takes no obvious pleasure from curtailing social freedoms doesn't make him any more inclined to submit his judgment to scrutiny or bind his own hands. He is still the same man whose first instinct last September was to set aside protocols of democracy in his impatience to get Brexit done.

The hazard now is not some sinister power grab by a despotic executive but something more subtle and gradual. It is that a government, less constrained by the normal operation of checking institutions, lets its entitlement to power expand into the newly available space.

Britain has a venerable tradition of liberal democracy and a less attractive tradition of congratulating itself for that history. At the same time it is routine to preface any judgment of the present situation by noting how much is unprecedented, which is only ever true for the shortest time because then the precedent has been set. And we do not know which democratic muscles in our body politic will atrophy from lack of use.

We are all putting a huge amount of faith in our democratic culture, hoping it is strong enough to link our historic record of civil rights, via a present that doesn't look much like the past, to an unknowable future. The bridge looks sturdy enough to bear the load; for now. But nothing is unprecedented twice. There are powers that democracies withhold from rulers because the taste for them, briefly sampled, is quickly acquired and not easily relinquished.