When the political cabinet met on Tuesday, by-elections were on the agenda. The Prime Minister is facing four of them. David Warburton, suspended from the party last year over a sex and cocaine ‘sting’, is the latest to step down. On 20 July the Tories will try to defend his constituency of Somerton and Frome, Boris Johnson’s old seat of Uxbridge and South Ruislip and Nigel Adams’s Selby and Ainsty.