Mayor of London. Enjoying high profile at Olympics. Wooing Tory MPs with more traditionalist agenda than David Cameron. New favourite to win leadership but critics say not serious enough to win a general election
Odds: 4-1 (William Hill)
Education Secretary. Seen as success story after wobbly start, extending Labour’s academy schools and bringing in free schools. Reluctant to run for leadership. But could be pressed into service as modernisers’ “Stop Boris” candidate
Chancellor. Stock has fallen in Tory circles since a disastrous Budget in March. Would be Cameron’s choice as his successor but some Tory MPs doubt he can recover. Prospects may turn on state of economy.
Defence Secretary. Dark horse coming up on the rails. Has impressed in minefield of Ministry of Defence after stint as Transport Secretary. But might lack the charisma to charm the Tory grassroots and voters.
Foreign Secretary. Enjoying life at Foreign Office after taking time out from frontbench. Older and wiser than the 36-year-old who became Tory leader in 1997. Plenty of admirers in party but some doubt he has appetite for leadership.
Former shadow Home Secretary. Either he or Liam Fox, the former Defence Secretary, could emerge as right-wing standard bearer. Critic of what he once dubbed the “Brokeback Coalition”. Could attract strong grassroots support.