Prime Minister Keir Starmer of Britain denounced what he called “the politics of grievance” on Tuesday, seeking to revive his plummeting approval numbers with a warning about embracing intolerance that was directly aimed at Reform U.K., the anti-immigration party that has surged in popularity across the country.
With Scottish, Welsh and a fresh set of municipal elections just eight months away, Mr. Starmer said in his annual speech to Labour Party loyalists that the choice facing British voters between Labour and Reform is a “fork in the road” that will determine the fate of the country’s democracy.
“We can choose decency. Or we can choose division. Renewal or decline,” he said. “It is a test. A fight for the soul of our country, every bit as big as rebuilding Britain after the war.”
Mr. Starmer’s words underscore the political threat to his party from Nigel Farage, the leader of Reform, whose approach to immigration and economics echoes President Trump. Having once described mass deportations as a “political impossibility” in Britain, Mr. Farage recently changed course, presenting a plan to deport hundreds of thousands of people, including some who had previously been granted a long-term right to remain in Britain.
Mr. Farage is not the only hazard for Mr. Starmer’s leadership. Last week, speculation was rife about a potential challenge to him from Andy Burnham, the mayor of Manchester and one of the Labour Party’s more charismatic communicators. The three-day party gathering in Liverpool underlined deep frustrations inside Mr. Starmer’s coalition of supporters about whether he has the ability and communication skills to set a clear political direction and lead the party to a second general election victory.
There are also divisions inside Labour over Israel’s war in Gaza, with some members of Parliament denouncing Mr. Starmer for not more quickly recognizing a Palestinian state and not taking a harder line with Israel’s government to end the killings in the embattled enclave.
But they also acknowledged the frustrations of voters who say they are disappointed with the government’s failure to enact the sweeping transformation they promised during the last election. In speeches in the conference hall and in conversations on its sidelines, Labour activists noted the slow pace of change, the stuttering economy and a series of missteps, including botched efforts to make it harder to claim welfare and to cut subsidies for home heating.
Those points were at the heart of Mr. Burnham’s criticism of Mr. Starmer, pointedly made in a series of interviews and remarks in the week leading up to the party conference.
Having broken ranks — and provoked a backlash from some Labour lawmakers — Mr. Burnham played down his leadership ambitions in speeches on the fringes of the conference. He emphasized the practical obstacles in his path if he wanted to replace Mr. Starmer as the party’s leader and the prime minister — elected as a regional mayor, he would first have to resign and then stand for election as a lawmaker in a parliamentary seat. There is no guarantee a suitable vacancy would arise.
“I can’t launch a leadership campaign. I’m not in Parliament. So that is the bottom line,” he said, at an event in a packed bar where he stressed his love for his current job.
Still, in an hourlong question-and-answer session, Mr. Burnham outlined an agenda that was more expansive than Mr. Starmer’s, arguing for changes to the country’s strict government debt rules to permit more public investment, and saying he hoped Britain would rejoin the European Union in his lifetime. (While Mr. Starmer opposed Brexit, he has been careful not to reignite that debate.)
Mr. Starmer’s allies raced to defend him against the challenge from Mr. Burnham. In a fiery speech on Monday, Rachel Reeves, the chancellor of the Exchequer, took aim at the mayor’s call for more spending, without naming him.
Against a challenging economic backdrop, many analysts believe that the government’s next test will come in November when Ms. Reeves is scheduled to deliver a budget that is widely expected to raise taxes.
In spite of Labour’s dire position in the polls, the mood was not entirely despondent. A combination of Mr. Burnham’s intervention, the rising threat from Reform and shock at the scale of a recent far-right rally in London appeared to have galvanized many in the party. Several government ministers gave impassioned speeches on Sunday night at a crowded event in a bar.
“We are the disinfectant that is going to clean up the pollution of the far right in our politics,” said Steve Reed, the housing secretary, who added that Labour must “show the people of this country that we are on their side, that we are making the difference that will transform their lives.”
Fighting to be heard amid the hubbub, Bridget Phillipson, the education secretary, told the party members that “divided parties don’t win elections and we won’t beat Reform if we are arguing among ourselves.”
She also appealed to them to be more vocal in campaigning. “We have got to be out there telling the positive story of what this Labour government is delivering,” she said. “If we don’t make that case, nobody else will.”