LONDON - Despite a string of stinging defeats in Parliament this week, and the resignation of his own brother on Thursday, Sept. 5, Prime Minister Boris Johnson continued his push for an early general election that he hopes would help him deliver Brexit by Oct. 31.

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

In the middle of the most brutal week of his six-week-old government, Johnson also suffered a personal blow Thursday when his younger brother Jo Johnson resigned 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," he tweeted, using the hashtag #overandout.

A Downing Street spokesman called Jo Johnson "a brilliant, talented minister and a fantastic MP," adding that the prime minister, "as both a politician and brother, understands this will not have been an easy matter for Jo."

Jo Johnson voted against Brexit in a 2016 referendum, and his ideological disagreements with his brother are well known, but this move was unexpected and underscored the depth of the country's divisions over Brexit and the prime minister's political problems.

Boris Johnson did get an assist on Thursday from visiting Vice President Mike Pence, who 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.

The question of when - rather than if - to hold a general election for the 650 seats in the House of Commons appears to be the latest Brexit battleground.

Boris Johnson was scheduled to give a speech Thursday to argue to the public that an Oct. 15 election was needed ahead of a key Oct. 17 Brexit-related meeting with EU officials.

Government officials said Johnson would argue that voters should be allowed to choose between Johnson, who would accept no further delays in Brexit, and Corbyn, who would go to Brussels and seek "more delay, more dither" and accept "whatever terms Brussels imposes over our nation."

John McDonnell, a top Labour Party lawmaker, responded that Johnson, whose plans were resoundingly slapped down in Parliament three times in 24 hours, was acting like a toddler throwing a tantrum who needed to "grow up."

McDonnell said Labour was eager for an election to unseat Johnson, but only when the party had a guarantee that Britain would not "crash out" of the EU without a deal on trade and other key issues - a prospect called the "no-deal Brexit."

"Fine, have your tantrum," McDonnell said Thursday on Sky News. "But we are not going to allow you take this country out on a no-deal Brexit, because you will undermine our economy."

After just six weeks on the job, Johnson's government is in turmoil.

Parliament is nearing final approval of a bill that would bar a no-deal Brexit without lawmakers' approval. That legislation also seeks a three-month delay in Brexit if no terms can be reached before the Oct. 31 deadline. The House of Lords, after debating well into the night Wednesday, cleared the way for the bill to go through by Friday.

Many analysts predict a that no-deal Brexit would lead to food and medicine shortages and chaos at borders. The European Union has set aside $858 million in disaster relief funds to help its member countries harmed by a no-deal Brexit.

Johnson has called such predictions "shameless scaremongering."

The prime minister also lost his governing majority this week through defections from rebellious party members and his remarkable decision to expel from the party any lawmakers who voted against him. Some of those kicked out this week were among the most experienced and honored members of the party.

The party was still reeling Thursday from those expulsions. Damian Green, a former senior member in the government of Johnson's predecessor, Theresa May, has called for the reinstatement of the rebels.

Representing a group of more than 100 Conservative members of Parliament, Green said that Johnson appeared to be "purging" moderates from the party, which he said was a risky move.

"I'm afraid it does look as though somebody has decided that the moderate, progressive wing of the Conservative Party is not wanted on the voyage," he told the BBC. "Now that's wrong in principle because there are many Conservative traditions, but it is terrible practical politics to narrow your appeal just before a general election."

One of those purged was Nicholas Soames, 71, a 37-year veteran of Parliament and the grandson of Winston Churchill. He told the Guardian Thursday that many Conservative lawmakers agreed with his defiance of Johnson's no-deal Brexit threat; he said he had received more than 500 emails from people thanking him.

"In a debate in the House in 1938, Chamberlain accused my grandfather of undermining his negotiations with the Germans," he said, referring to Neville Chamberlain, the prime minister at the time. "I think history will prove my grandpapa to be right under the circumstances. And I think I will prove to be right."

Like the Churchill family drama, the resignation of Jo Johnson was a hugely symbolic.

Much as the rest of the nation, the Johnson family is deeply divided on Brexit. Jo Johnson has previously called for a second referendum on the issue, after the one in 2016.

Rachel Johnson, their sister, ran unsuccessfully in European elections earlier this year as a pro-EU candidate.

Despite their differing views, they appeared to rally around their big brother in recent weeks. Both siblings, along with their father Stanley Johnson, were in the audience to hear Boris Johnson's speech on the day he became leader of the Conservative Party.

Jo Johnson became a lawmaker in 2010 and held a number of ministerial roles. He had accepted a position in his brother's government as a junior minister in the departments of education and business.

Boris Johnson has argued all week that he has been making "great progress" in negotiations with European officials to reach a deal before Oct. 31. He has said that a key weapon in his negotiating arsenal is his willingness to leave without a deal, "do or die." He said lawmakers, who have now taken that leverage away from him, have undermined his ability to negotiate and acted "to stop, to scupper any serious negotiations."

Corbyn and others have said they do not believe there are serious negotiations with the European Union underway, and they suspect that Johnson is simply trying to "run out the clock" until Britain "crashes out" of the EU on Oct. 31.

In Brussels, frustration with the British drama was running high. Senior negotiators have all but given up on discussions with Johnson's team for now, seeing little point in making plans with a group that could soon be swept out by elections. Nor have British negotiators brought any new ideas that could be the subject of negotiations, officials said.

"There's been no concrete proposals yet. It's all smokescreen," said a senior EU diplomat, speaking on condition of anonymity to discuss the sensitive - if apparently lacking in substance - talks.

Johnson's Brexit negotiator, David Frost, was in Brussels on Wednesday for more than five hours of discussions. But there was little on the table to discuss, the European diplomat said.

"I don't know what they talk about," the diplomat said.

EU officials say that although they are keen to avoid the chaos of a no-deal Brexit, they are unwilling to compromise on their demand for ironclad guarantees that the Irish border remain open, although Johnson has suggested otherwise in Parliament.

But they also said that EU leaders had no plans to push Britain out of the European Union against its will, and that if Johnson asked to delay his country's exit date to hold a general election, he would almost certainly be granted the reprieve.

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This article was written by Kevin Sullivan and Karla Adam, reporters for The Washington Post.

The Washington Post's Michael Birnbaum in Brussels contributed to this story.