Rishi Sunak is the UK's third prime minister in less than two months - the fifth in six years. It is the fastest turnover of leaders in No 10 for nearly a century."There is far more focus from voters and politicians on party leaders and rather less on the party as a whole - that means that the leader is often held personally responsible for anything that goes wrong," said Tim Bale, professor of politics at Queen Mary University of London. Professor Bale also featured in The Independent, LBC, BBC News 24, CNN, Sky News and UKandEU, BBC World Service and various regional BBC radio stations