Theresa May, U.K. prime minister, leaves number 10 Downing Street following a meeting with Estonia's Prime Minister Juri Ratas in London, U.K., on Tuesday, Jan. 30, 2018. Brexit campaigners in the U.K.'s governing Conservative Party would be "foolish" to try to overthrow May, Cabinet minister Liam Fox warned, as the prime minister battles critics on multiple fronts.