Dominic Cummings has said it is his “duty to get rid” of Boris Johnson as prime minister, describing it as “sort of like fixing the drains”. The prime minister’s former chief adviser called his former boss a “complete fuckwit” whose only preoccupations were “Big Ben’s bongs” and “looking at maps” to “order the building of things” in his honour. Cummings, who has sent evidence to the Cabinet...