British Finance Minister Philip Hammond resigned yesterday amid speculation that at least half a dozen lower-ranking ministers may also jump ship over the coming days. Hammond, who is vehemently opposed to a "no-deal Brexit" that Johnson has not ruled out, said in a letter to outgoing Prime Minister Theresa May that the unresolved issue of Brexit had caused "uncertainty" for the economy. His resignation thrusts the understated political veteran into the middle of a brewing revolt against new Prime Minister Johnson's Brexit strategy.

Pro-EU Foreign Office Minister Alan Duncan announced Monday that he was also quitting "in anticipation of the change on Wednesday." "It is tragic that just when we could have been the dominant intellectual and political force throughout Europe, and beyond, we have to spend every day working beneath the dark cloud of Brexit," he wrote in his resignation letter to outgoing Prime Minister Theresa May.

Three ministers timed their resignations around the announcement of Johnson's leadership victory. Justice Secretary David Gauke, Secretary of State for International Development Rory Stewart and Education Minister Anne Milton quit the government shortly before the Conservative party announced Johnson's victory.

Johnson began putting together his top team on a mission to deliver Brexit by Oct. 31 by any means necessary. Many members of his administration will be strong Brexit supporters like Johnson, but he is also set to include some pro-EU politicians. In a sign he hopes to move beyond the largely white, male and affluent Conservative Party members who chose him as their leader, Johnson's office said he will put together a "Cabinet for modern Britain," with a record number of ethnic-minority lawmakers. Johnson has vowed that Britain will leave the EU on the currently scheduled date, with or without a deal on departure terms. Economists warn that a no-deal Brexit would disrupt trade and plunge the U.K. into recession, and the EU is adamant that the deal it made with May would not be renegotiated. Chief EU Brexit negotiator Michel Barnier said, "We are ready to listen and to work with" Johnson, but did not budge on the bloc's refusal to alter the deal. "A no-deal Brexit will never be, never, the choice of the EU. But we are prepared," he said in Brussels.