MANCHESTER, England — First there was the prankster, theatrically handing her a notice that she was being fired. Then her voice went and a persistent cough disrupted her delivery, making her speech often painful to the ear.
Politics can be a cruel business, and just when Britain’s prime minister, Theresa May, needed a rousing, commanding speech to restore her authority over her warring Conservative Party, she had a nightmare.
Ending a party conference dominated by speculation about her fragile leadership, May struggled her way through her set-piece address Wednesday, the audience periodically giving protracted applause to allow her time to rest her croaking voice.
She repeatedly drank from her glass of water, and at one point the chancellor of the Exchequer, Philip Hammond, handed her a cough lozenge. Sometimes she seemed almost to be reduced to a faltering whisper.
Then, toward the end of the address, letters began to fall from the slogan behind her onstage.
The speech highlighted the problems confronting May — her battle to complete it seeming to some like a metaphor for her struggling premiership, the set of mishaps overshadowing the messages she hoped would dominate the news.
The four-day conference in Manchester is the first since May gambled by calling a general election in June, in which her Conservative Party lost its majority after an unexpectedly strong performance from the opposition Labour Party, destroying much of her authority in the process.
Under the left-wing leadership of Jeremy Corbyn, Labour’s anti-austerity message struck a chord, particularly with younger voters, who turned out in greater numbers than usual, leaving many Conservative activists in Manchester wondering how to compete.
As the debate about the Conservative Party’s future has unfolded at the conference center and beyond, May’s potential successors have had a chance to grab the limelight, and none took that opportunity more ruthlessly than the foreign secretary, Boris Johnson, who has made two interventions undermining May’s strategy for negotiating Britain’s withdrawal from the European Union, known as Brexit.
While there seems to be no immediate plot to unseat May, analysts say that the longest she can expect to remain in her job is until March 2019, when the withdrawal is to take place. The party conference, and this speech in particular, was an opportunity to reassert her authority over a Cabinet squabbling over the details of Brexit.
On Wednesday, May promised that more homes would be built to tackle the country’s housing crisis, detailed a cap on energy prices, and promised to forge a British version of the American dream.
She also apologized to Conservative Party members for leading an election campaign that was “too scripted, too presidential.”
But May was soon interrupted by a prankster, who handed her a P45 — a form that is sent to Britons who lose their jobs — saying “Boris asked me to give you this,” before being ejected from the hall.
Though the episode raised some security questions, police later said that the man, Simon Brodkin, a comedian, had accreditation to attend the conference. That was despite the fact Brodkin performs as a character called Lee Nelson, whose website mentions pranks including disrupting a news conference by throwing bank notes at Sepp Blatter, the former president of FIFA, the governing body of international soccer.
May’s colleagues came to her defense, saying that her performance illustrated her determination, and that voters would understand and sympathize with her predicament.
Jeremy Hunt, the health secretary, described it as the “ultimate tough gig,” but said that “she battled on,” and that “what the public will take away from that, curiously, is that sense of duty.”
Nevertheless, there will no doubt be frustration among May’s allies that a speech that had been going well until the interruption spiraled out of control, overshadowing announcements that had sought to wrest attention from Corbyn’s agenda.