Mr. Raab’s suitability for leading the country through a time of national crisis is another matter. While the prime minister and his team trust him more than Mr. Johnson does most senior cabinet ministers, Mr. Raab is a relative unknown to the public and is seen to lack warmth as a speaker.

But even if Mr. Raab defies his critics, there are limits to how much a high-performing de facto deputy can achieve. The British system is not built for a situation in which its leader is absent for a prolonged period of time — let alone during a national crisis. There are not clear guidelines for who takes power if the prime minister is incapacitated. And Mr. Raab is not carrying out all of Mr. Johnson’s duties: He is not working from 10 Downing Street, he will not meet with the queen, and he does not have the power to fire or hire members of the cabinet.

Since Mr. Johnson became prime minister, power has been broadly balanced among the four ministers tasked with heading the coronavirus subcommittees: Mr. Raab, Chancellor Rishi Sunak, Health Secretary Matt Hancock and the chancellor of the Duchy of Lancaster, Michael Gove. There have been repeated reports of egos clashing behind the scenes over who leads the public response, competing briefs and turf wars. Now they must put their differences aside and find a way to work their competing interests into a joint plan.

The government has been reluctant to even discuss what an exit strategy from the lockdown might look like, on the grounds that it could lead people to relax social distancing. In truth, it’s also because there are rival views in government on what should happen: Some ministers think the lockdown must be eased in the coming weeks to salvage the economy, while others see that as a damaging gamble on people’s lives.

But this is the kind of decision that should rest only with an elected prime minister. Those sending Mr. Johnson well wishes are doing so not only for his own well-being but also for the sake of the country. The best hope is that he makes as speedy a recovery as possible.

Mr. Raab used Tuesday’s government news conference to tell the public that he believes Mr. Johnson “will be back at the helm leading us through the crisis in short order.” But if that is not possible, serious thinking needs to be done on how major policy decisions should be made and by whom. The current arrangement is not suited to a prolonged absence of the prime minister.

Katy Balls (@katyballs) is the deputy political editor of The Spectator.

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