With the prime minister in intensive care due to coronavirus, foreign secretary Dominic Raab has been deputised to take his place at the head of government.
But what powers does Boris Johnson’s stand-in have, exactly? And is he effectively prime minister, on a temporary basis?
“There are differences,” said Catherine Haddon, senior fellow at the Institute for Government. “The prime minister remains the prime minister – he’s the one who kissed the hand of the Queen and unless or until he resigns – or in any other way is removed from or leaves office – he continues to be the prime minister. So in that sense he constitutionally retains that level of authority.”
Key to understanding what powers Raab now has is understanding what powers the prime minister has in the first place.
Under the UK constitution, executive decisions are actually taken by the cabinet as a collective body, rather than the prime minister. Whether this is actually the case in practice depends on the style of the sitting prime minister on their degree of political authority – whether they can get their way without a mutiny.
“The prime minister’s powers are largely informal; most statutory powers sit with secretary of states [members of the cabinet],” Haddon explains.
“So it’s entirely possible for him to delegate those responsibilities to somebody else ... effectively, he’s first among equals and while he’s not there you can have somebody else doing the day to day job that he would be doing.”
Robert Hazell, professor of government and the constitution at UCL’s Constitution Unit, explains that Raab will effectively take over the prime minister’s official functions that require the presence of a physical person.
“Dominic Raab will chair meetings of cabinet and cabinet committees, will sum up the discussion and announce their collective decision, and will represent the government at press briefings – unless he appoints someone else to speak for the government, such as Matt Hancock, if the briefing is primarily about health, for instance,” he says.
But Hazell notes that Raab won’t be doing this alone: he will be supported by the senior civil service, including Sir Mark Sedwill, who “is now very experienced as cabinet secretary” as well as “the whole cabinet office machine, as well as the people in No 10”. The prime minister may be in charge, but parts of government effectively run themselves as it is.
Haddon adds: “It really comes down to different aspects of it: sitting in No 10, getting all the papers that the prime minister would have, chairing the meetings, there’s no reason why another minister can’t take those on.
“In terms of decision making, it is the cabinet as a collective that make decisions, so it is possible for the cabinet to carry on in an absence of the formal post of the prime minister.
“Most of the basis on which he’s able to do this role as a deputy is because it’s been conferred on him by the prime minister, but also with the acquiescence of the rest of cabinet.”
It is this approval of the cabinet – and the question of political authority – that specific decision-making powers come down to.
Thus, Downing Street has said Raab and the cabinet will have “authority and ability to respond” with military action in absence of Johnson. But he will not be able to fire or hire ministers, and is eschewing weekly audiences with the Queen.
A Downing Street spokesperson on Tuesday was keen to refer to the machine around the prime minister, telling reporters that “the UK has a robust national security architecture, including the National Security Council, which is designated to be resilient and able to operate effectively under different circumstances”.
General Sir Nick Carter, chief of the defence staff, told the BBC he believed there was a “very clear” chain of command because the National Security Council, which includes senior cabinet ministers, is “wrapped around” the prime minister. The only area the government is declining to clarify is who controls the UK’s nuclear codes.
It’s important to note that similar situations aren’t that unusual: prime ministers do go on holiday, but, Haddon notes, they are usually at least contactable for the big calls.
“Every time when the prime minister goes on holiday someone else is usually sitting in No 10 doing the deputy work for them,” she says. “It’s always a thing in silly season who is going to be sitting and minding the shop for them.”
Hazell adds: “There are plenty of precedents for senior members of the government deputising in the PM’s absence; but none in quite such an emergency as the present crisis.”