Rachel Reeves has said Labour is "not a party of protest" as her keynote conference speech was disrupted by hecklers.
In her first conference speech as chancellor, Reeves received applause and a standing ovation as she began.
But shortly afterwards a protester was hauled out while complaining about the government's arms sales to Israel.
The chancellor shot back: "this is a changed Labour Party, a Labour Party that represents working people, not a party of protest."
Campaign group Climate Resistance claimed responsibility for the protest.
Reeves' speech, a little over a month before her first Budget on October 30, was an attempt to strike a more optimistic tone about the UK's economy after months of gloomy messages about the inheritance she was left by the Tories.
She said: "because I know how much damage has been done in those 14 years, let me say one thing straight up: there will be no return to austerity. Conservative austerity was a destructive choice for our public services and for investment and growth too.
"Yes, we must deal with the Tory legacy and that means tough decisions but I won't let that dim our ambition for Britain.
"So it will be a budget with real ambition, a budget to fix the foundations, a budget to deliver the change that we promised, a budget to rebuild Britain."
In her speech, she announced that free breakfast clubs in England will start to be rolled out from April in hundreds of schools.
It was, she said, "an investment in our young people, an investment in reducing child poverty and investment in our economy."