In his absence, Boris Johnson’s British Government has mainly followed the lockdown strategy that was determined before the Prime Minister was infected with Covid-19.

Many are hoping that he will soon return to work and change course; that he’ll celebrate signs of a flattening infection curve and reopen Britain for business. It’s unlikely to work out that way.

It’s true that you almost expect Johnson to bound up to the cameras and change the narrative. His modus operandi throughout his career has been Tiggerish enthusiasm. The politician who banished the “gloomsters and doomsters” on Brexit and championed the three-word campaign slogan — “Take Back Control” and “Get Brexit Done” — might well have been expected, before his illness struck, to make “Lift the Lockdown” his mantra.

Even if Johnson looks and sounds much the same when he returns to full-time work, the experience of serious illness and a forced leave of absence as thousands died must have affected his sense of mission.

Johnson had often used the country’s National Health Service as a prop when building his case for Brexit and his election campaign — leaving Europe, he argued speciously, would free money to spend on healthcare.

Will he not now do more to support an underfunded, overstretched and ill-equipped service that he credits with saving his life?

There will certainly be no immediate rush to relax the lockdown strictures. Foreign secretary Dominic Raab, who has deputised for Johnson, has already extended the measures by another three weeks. Still, as other nations begin to loosen controls, the clamour will grow louder in Britain, too.

Last week Raab announced five tests that would determine the timing for a reopening of Britain. The first three are fairly straightforward: the Government must be confident that the NHS can provide sufficient care across the country; there must be a sustained fall in the daily death rate; and there needs to be evidence that the infection rate is decreasing.

The fourth test — confidence that the supply of testing and personal protective equipment for medical workers can meet demand — is more vague. The UK is increasing testing, finally, but it’s a long way from the kind of regimes put in place in East Asian countries that quickly suppressed the spread of the virus, including contact tracing. Germany is well ahead on this, too.

PPE shortages, one of the unnecessary tragedies of this outbreak, persist, as the British Medical Association and doctors repeatedly note. And yet Raab’s fourth target doesn’t specify what levels of testing and PPE need to be delivered.

Even if the Government fixes these problems, the fifth test is that there can be no risk of a second peak in infections from relaxing the lockdown. While Johnson is a political gambler who favours the bold stroke, he surely wouldn’t open the sluice gates and let a new wave of infections wash away the stability built through social-distancing and curtailed activity.

Indeed, Bloomberg News reported on Monday that in Johnson’s conversations with Cabinet members, he emphasised caution.

Updated models based on more recent infection data will offer some basis for judgment, but a guarantee against a serious second wave of Covid-19 will require a vaccine or widespread testing and contact tracing. Neither are certainties, suggesting that social-distancing measures of some sort will be around for a while.

A report released on Monday by the Tony Blair Institute for Global Change argues that since a total lockdown isn’t sustainable, the Government should use hard metrics for its five tests and phase in some liberalisation.

For example, it could specify that if there were fewer than 500 new daily cases, testing capacity had expanded to more than 100,000 people per day, and contact tracing was widespread, then conditions could be set for a return to the workplace for individuals not in a high-risk category and for schools to reopen.

It’s not a bad suggestion, but where to put the thresholds and how to manage the complexities of restrictions are ultimately political decisions for Johnson and his cabinet.

The pressure is on to find some way to ease up. The Office for Budget Responsibility estimates a massive drop in national income during the second quarter if the lockdown persists through June. Unemployment is expected to rise by two million to 10 per cent from historic lows. That blow may be temporary, but the longer the economic shutdown lasts, the greater the risk of lasting damage.

There is also the impact on the business sectors that Johnson most wanted to “level up” — to help working-class communities — with new investment and infrastructure spending.

The Institute for Fiscal Studies estimates that one third of employees in the lowest-earning part of the income distribution chart are in sectors that have been mostly or completely shut down.

If, as some have argued, restrictions are lifted by age group, there are questions about how that would be enforced. Johnson has set himself a unifying mission to keep the support of the ex-Labour Party voters who delivered him a handsome election victory.

He will have to find ways to restart the economy that don’t ignore or further worsen inequalities. It is hard to imagine Johnson releasing wealthier parts of the country from lockdown while poorer areas languish under restrictions. But some phasing will be necessary.

These decisions will have a profound impact, not only on the fight against the coronavirus, but on the economic recovery and on how politics is redefined through this crisis. And they come amid growing scrutiny of Johnson’s early handling of the outbreak.

The Government has spent much of the past two days trying to rebut a Sunday Times investigation of how it did too little too late.

Johnson’s mistakes will be subject to a proper inquiry in time. His challenge when he returns will be to avoid compounding them.

• Therese Raphael writes editorials on European politics and economics for Bloomberg Opinion. She was editorial page editor of The Wall Street Journal Europe