This turned Ms Braverman into a kingmaker, and in her letter she recalled the price she had exacted for preserving party unity by staying in his cabinet. Under their alleged deal, her demands were: tough curbs on both legal and illegal migration; sticking with Boris Johnson’s Brexit deal for Northern Ireland; and tighter control of sex education in schools. “You have manifestly and repeatedly failed to deliver on every single one of these key policies,” she wrote. “I can only surmise … you have no appetite for doing what is necessary.” Downing Street issued a brief statement in response, thanking...