LONDON — Despite a string of stinging defeats in Parliament, and the painful, public resignation of his brother, Prime Minister Boris Johnson on Thursday continued his passionate push for an early general election he hopes would help him deliver Brexit by Oct. 31.

Johnson cast his quest to bust Britain out of the European Union in defiant and populist terms, saying he would “rather be dead in a ditch” than seek any further delays to Brexit.

He said he didn’t want to see “the “powers of the British people handed over to Brussels, so we can be kept incarcerated in the E.U.” That echoed the populist — and successful — appeal to British voters to “take back control” of Britain that led to the passage of Brexit in a 2016 national referendum.

Still, the tumult of the past week appeared to be taking a toll on Johnson, who was unusually halting and uncertain as he spoke before a group of police cadets in Yorkshire. Normally a gifted and confident orator, Johnson squinted awkwardly into the bright sunshine. He stumbled as he tried to recite the British equivalent of the Miranda Rights to the cadets, who know the lines well.

That may have been especially understandable on a day he suffered the personal blow of having his younger brother Jo Johnson resign as a member of Parliament and government minister.

“In recent weeks I’ve been torn between family loyalty and the national interest — it’s an unresolvable tension & time for others to take on my roles as MP & Minister,” Jo Johnson tweeted, using the hashtag #overandout.

Jo Johnson voted against Brexit in the 2016 referendum, and his ideological disagreements with his brother are well known. But his resignation was unexpected and underscored the depth of divisions over Brexit and of the prime minister’s political problems.

“Jo doesn’t agree with me about the European Union. It’s an issue that divides families and divides everybody,” Boris Johnson said in Yorkshire, calling his brother a “fantastic guy” and noting he supported the government’s efforts to increase spending on education, hospitals and public safety.

Asked if he would be the next Johnson to resign, the prime minister didn’t answer directly but said he was determined to “deliver on the mandate of the people” from the 2016 Brexit referendum.

The embattled Johnson got a supportive assist on Thursday from visiting Vice President Mike Pence, who met with him at 10 Downing Street and suggested a post-Brexit trade deal could “increase trade between our countries by three or four times.”

“The United States is ready, willing and able to immediately negotiate a free-trade agreement with the U.K.,” Pence said.

Johnson has been criticized by his opponents for being too deferential to the U.S. administration. Labour Party leader Jeremy Corbyn has charged that Johnson would bring the U.K. “a one-sided United States trade deal that will put us at the mercy of Donald Trump and the biggest American corporations.”

The United States and Britain can’t strike a trade deal until after Brexit. And whether Johnson would be around to negotiate it is unclear.

Parliament has rebelled against his position that the U.K. should be willing to leave the E.U. on Oct. 31 without a withdrawal deal to manage the transition. The House of Commons passed legislation on Wednesday designed to avert a chaotic no-deal Brexit next month. That legislation seeks a three-month delay in Brexit if no terms can be reached before Oct. 31.

The House of Lords, after debating late into Wednesday, cleared the way for the bill to get final approval by Friday.

The big battle seems to be when — rather than if — to hold a general election for the 650 seats in the House of Commons.

Johnson’s government on Monday plans to introduce new legislation again seeking an early election, despite Parliament’s rejection of such a plan on Wednesday night, officials said.