LONDON — Mr Nigel Farage had one of the great personal victories in British politics this year, pushing Britain, through his UK Independence Party (Ukip), into voting in June to leave the European Union.

Yet having accomplished his goal, Mr Farage quit as leader of the party, which has experienced a comedy of errors ever since, damaging its reputation and calling its very survival into question.

The favourite to lead the party, known for its populist denunciations of immigrants, Mr Steven Woolfe, was disqualified from the leadership race when he got his application in too late, blaming a faulty PayPal connection. Ms Diane James, who won, lasted only 18 days before resigning and causing Mr Farage to come back as temporary leader.

Then, this month, an argument during a meeting of UKIP members of the European Parliament in Strasbourg, got out of control, and Mr Woolfe wound up in a hospital for three days. He said he had been hit by another party member, reportedly after saying that with the referendum won, he was considering quitting Ukip and rejoining the Conservative Party. His opponent, a former soldier named Mike Hookem, has denied throwing a punch.

After the resignation of Ms James, Mr Woolfe put his name forward again for the leadership, but on Monday (Oct 17), he quit altogether, telling the BBC that Ukip is “in a death spiral” and that there is “something rotten” in the party, which is riven with “infighting.”

The party had “no future” without Mr Farage, who held it together, he said. But Mr Farage, who has helped advise Donald Trump in the United States, has said he has no intention of returning to run Ukip.

Mr Woolfe said that he would remain a member of the European Parliament, representing northwest England as an independent, and that he had made a complaint to the police against Mr Hookem, who he said had given him “a blow to the face,” knocking him backward.

Mr Hookem has acknowledged a “scuffle” but said he “categorically did not” throw a punch at his colleague and has threatened legal action for defamation.

Mr Woolfe said that the two men had exchanged heated words at the party meeting in Strasbourg and that he had told Mr Hookem, “Let’s go outside and discuss this man-to-man” — insisting that he meant verbally.

Asked what happened next, Mr Woolfe said: “He rushed at me. A blow to my face forced me back through the door,” and he fell and hit his head.

He recovered, though doctors kept him in the hospital for observation after he suffered two seizures.

Mr Woolfe was the favorite to lead Ukip, with the backing of a major donor, Mr Arron Banks, who has spoken about starting a different party to appeal to working-class Labour voters who have been attracted to UKIP’s nationalism and campaign against high numbers of immigrants. THE NEW YORK TIMES