Labour officials faced boos and jeers after unions complained about moves to delay a conference debate on winter fuel payment cuts.
Unite and the Communication Workers Union (CWU) put forward a motion calling for the decision to introduce means-testing for the benefit to be reversed.
It was expected to be debated on Monday afternoon, shortly after Chancellor Rachel Reeves delivers her speech and the day before Prime Minister Sir Keir Starmer takes to the stage in Liverpool.
But sources said unions were told late on Sunday that the debate is being moved to Wednesday morning, a time when many delegates will have left the conference.
From this winter, only people on pension credit or certain other benefits will receive the payments, worth up to £300, while about 10 million others are set to be stripped of the allowance.
The Government has said the move is necessary to help fill a “£22 billion black hole” in the public finances inherited from the Tory government.
Complaints were raised about the decision not to schedule the motion at the start of conference on Monday, with Unite’s Andy Green saying: “This is simply an attempt to take out the debate on the winter fuel allowance.
“Today is economy day at conference and we have the Chancellor speaking and a composite motion on the growth mission, which is scheduled for this morning.
“So, it is more of a surprise, in fact an outrage, to us that the composite motion from Unite and the CWU on economy for the future is not listed on the agenda for today.
“It is disrespectful to our members and every single delegate here and conference itself, who voted for the priorities ballot.”
Some delegates booed Labour officials at its party conference (Peter Byrne/PA)
CWU’s senior deputy general secretary Tony Kearns questioned why the motion was not scheduled and why it has been briefed that “it’s unlikely to be scheduled for debate this week”.
Lynne Morris, who chairs the conference arrangements committee (CAC), was heckled and booed by some delegates as she said: “This is a really busy conference and we are trying to accommodate as much as we can, and I’m going to take this back straight to CAC and I’ll come back to you with an answer asap.”
Wendy Nichols, who was chairing the morning session of conference, said people should not be booed at conference.
She said: “We’ve all got different points of view but surely we should show respect to each other and let’s not continue the way it is today.”
Ms Nichols added: “Shouting from the back at somebody like me doesn’t work.
“This conference is being looked at all over the country, so let’s show a little bit of respect for each other and stop all the shouting and booing and everything else, it does us no favours.”