London(CNN) Before British Prime Minister Boris Johnson went into intensive care on Monday evening with worsening coronavirus-related symptoms, he asked his Foreign Secretary and First Secretary of State Dominic Raab to deputize for him "where necessary."
While now is a time of great uncertainty for the British public, Johnson's handing over of some duties to Raab should be relatively seamless and is unlikely to affect any immediate government business.
Less clear is what will happen if Johnson is incapacitated for more than a few days. There's no clear "Plan B" in Britain's constitution or in the Cabinet Manual -- which lays out the rules for running the government -- for who should take over if Johnson isn't able to lead the country, experts told Reuters.
One thing that should help in terms of continuity: Unlike in the United States, where a President might hail from a different party than leaders in Congress, the UK government is entirely comprised of members of Parliament from Johnson's party, which won the most seats in December's election -- meaning it operates as one entity.
Raab, a 46-year-old former lawyer, was elected to Parliament in 2010, and spent his entire political career on the same wing of the party that secretly yearned for Johnson to have a serious go at taking the reins.
Like Johnson, Raab is a longstanding advocate of Brexit who was willing to be a thorn in his own party's side when it had more pro-European leadership.
Despite his euroskeptic leanings, his qualities were noticed by that pro-European leadership, and when then-Prime Minister David Cameron won reelection in 2015, Raab was offered a job in government. At the time, Raab was seen as a rising star within the party, and his promotion was seen as a way for Cameron to bolster his own euroskeptic credentials.
Raab previously served in Theresa May's cabinet as the Brexit secretary, only to resign in protest at the deal she eventually struck with the EU. And despite running against Johnson in last summer's Conservative leadership contest, he has been extraordinarily loyal to the Prime Minister ever since.
While Raab is perhaps less socially liberal than Johnson, it is highly unlikely he would depart radically from the Prime Minister's agenda in the short-term -- not just because there simply isn't enough time to change government policy during a time of national crisis, but also because the UK cabinet works on the principle of collective responsibility.