It also emerged that Deputy Prime Minister Angela Rayner accepted the loan of a New York apartment for a holiday and that Chancellor Rachel Reeves accepted around £7,500 worth of clothing.
Reeves and the Labour party have defended the abolition of the £300 payment to many pensioners to help them heat their homes, citing a need to fill a “£22 billion black hole” they say was left by the Conservatives.
Starmer lost a symbolic vote at the conference demanding that he reverse the contentious policy.
The vote was non-binding but its outcome was nonetheless embarrassing for the premier.
It highlighted the strength of feeling among activists and union backers.
Delegates narrowly backed a union motion calling for the cut to be reversed.
“I do not understand how our new Labour Government can cut the winter fuel allowance for pensioners and leave the super-rich untouched,” said the Unite union general secretary Sharon Graham.