What would happen if British Prime Minister Boris Johnson's case of coronavirus — so far he has "mild symptoms" — were to become more serious or even incapacitate him and his team? Under Britain's uncodified constitution, the answer is unclear.
Johnson and Health Secretary Matt Hancock both have said they were able to keep working in self-isolation at home after confirming they had tested positive for the virus.
But the fact that two such crucial members of the British government have contracted the disease — and their top medical adviser is now self-isolating with symptoms — has raised questions about how the government would function without them at a time of global crisis.