Rival U.K. Political Leaders Clash in Bad-Tempered Election Debate

The two contenders to become Britain’s next prime minister clashed angrily over tax, immigration and health policy on Tuesday in a televised debate that at times descended into ill-tempered exchanges as the political rivals talked over each other.

The confrontation came exactly a month before a pivotal general election that will determine whether the opposition Labour Party can capitalize on its strong lead in opinion polls and end 14 turbulent years of Conservative-led government during which the party has had five different prime ministers.

Almost as soon as the debate started, Prime Minister Rishi Sunak claimed that his opponent, the Labour leader Keir Starmer, would raise taxes on Britons by 2,000 pounds a year if he won the election, repeating the claim numerous times. “Absolute garbage,” Mr. Starmer eventually responded.

The Labour Party said that the figure was based on faulty assumptions, and Jonathan Ashworth, a senior party lawmaker, claimed in an interview with Sky News after the debate that Mr. Sunak was lying. But Mr. Starmer’s failure to clearly reject the claim early in the broadcast set the tone for what followed: a solid but defensive performance by the opposition leader against an energized and at times ruthless opponent.

One snap opinion poll of viewers declared Mr. Sunak a narrow victor, although Mr. Starmer was seen as more likable and more trustworthy. While the debate is unlikely to swing significant numbers of votes, Mr. Sunak’s performance may have steadied some nerves inside his anxious party.