The Prime Minister remains Prime Minister until he resigns or is otherwise unavailable. Foreign Secretary Dominic Raab is the designated survivor.
Boris Johnson has no formal deputy. But as Covid-19 hit, it was briefed that his “designated survivor” is Raab. It was Raab who chaired the emergency Covid meeting on Monday morning and Downing Street said he would deputise “where necessary” while the PM is in hospital.
There is actually no official constitutional post of deputy prime minister, although the title has been given to political allies of Prime Ministers from time to time.
For now Raab takes over the fight against the virus and will also take security decisions as necessary.However, moving from his position as First Secretary of