How Boris Johnson Suffered a Stunning Political Reversal

When Boris Johnson won a landslide election victory for his Conservative Party in 2019, he loomed as a colossus over British politics, the man who had redrawn the country’s political map with a vow to “get Brexit done.”

With an 80-seat majority in Parliament, the greatest amassed by a Conservative leader since Margaret Thatcher in 1987, Mr. Johnson seemed assured of five years in power. Some analysts predicted a comfortable decade in 10 Downing Street for Mr. Johnson, the most reliable vote-getter in British politics.

Now, less than three years after that triumph, Mr. Johnson’s future was hanging by a thread on Monday. Rebels in his party have called for a no-confidence vote that could cost him his job; even if he wins and clings to his position, it could cripple him as an effective and credible leader. He faces that vote from his own party Monday night.

It is one of the most head-spinning reversals of fortune in modern British political history.

What happened?