Mr. Johnson promised that Britain’s Brexit negotiators would sit down with their European counterparts twice a week through September, with the possibility of additional technical meetings, to try to reach a deal that would avert the risk of a cliff-edge departure.

“While I have been encouraged with my discussions with E.U. leaders over recent weeks that there is a willingness to talk about alternatives to the anti-democratic backstop,” he said in comments released by his office, “it is now time for both sides to step up the tempo.”

Details: The Conservative Party leader in Scotland, Ruth Davidson, resigned, and Lord Young of Cookham, a former cabinet minister, resigned as a Conservative whip in the House of Lords on Thursday.

Meaning: The move seemed to acknowledge the mounting concern about the suspension of Parliament, a decision that provoked spontaneous protests in London and other cities.