LONDON — I am scared. The markets are scared. The politicians I have been talking to are scared, or livid.

A few days ago, Prime Minister Theresa May unveiled her deal with the European Union. Within 48 hours, Britain’s government spun into crisis. Mrs. May’s survival is threatened as furious prominent Brexiteers go public with their intention to unseat her. Four ministers have resigned, more resignations may follow and nobody believes that she has the votes to get her deal through Parliament. What happens after that is a conundrum.

The cause of this paralysis is the hard-line Brexiteers, a frighteningly powerful cohort within Mrs. May’s Conservative Party, a group that is heedless about economic damage to Britain in pursuit of a political goal.

The first minister to resign was Mrs. May’s Brexit secretary, Dominic Raab, a cold-eyed man in a hurry, a flintily ambitious Thatcherite. The bid to topple Mrs. May was initiated by Jacob Rees-Mogg, a vain, drawling member of Parliament, a financier who once campaigned alongside his nanny in a Mercedes and has built a career as a political rock star and possible leader on the back of such affectation. They join an earlier defector, the flailing, floppy-haired Boris Johnson, a man who is half-crazed by his repeated failure to become the Conservative Party’s leader and who is desperate to grasp at his last chance, even if it means undermining the country.