Two former ministers said they could not stay in a party led by Jacob Rees-Mogg

Senior Conservatives have launched a search for a “Stop BoMogg” candidate to prevent Boris Johnson or Jacob Rees-Mogg becoming prime minister in a sudden leadership contest.

One cabinet minister privately warned that there was a “whiff of death” about Theresa May’s premiership.

Two Remain-supporting former ministers, Justine Greening and Anna Soubry, yesterday suggested they could not stay in a party led by Mr Rees-Mogg, who has emerged as a frontrunner to replace Mrs May. There is growing unease among the parliamentary party mainstream that the party could be “captured” by hard-right supporters of an extreme version of Brexit.

While Mr Johnson and Mr Rees-Mogg have emerged as favourites to become Tory leader, their opponents have yet to identify a candidate. Amber Rudd, the home secretary,