Labour cannot promise free school meals for all primary school children because there is not an “endless supply of money”, Angela Rayner has said.
Keir Starmer has been under pressure to introduce the policy should he become prime minister after the election.
Sadiq Khan, London’s Labour mayor, has announced free school meals will be offered to all primary school children in the capital for a year from September.
The National Education Union (NEU) has also called on Labour to commit to the policy if it forms the next government.
But speaking at the Institute for Government (IfG) on Thursday, Rayner said Labour could only pledge to provide free breakfasts.
“The free breakfast club is going to have the biggest impact that’s why we have prioritised to do that,” she said.
“We haven’t got an endless supply of money. We know that the economy is in a terrible place.
“We know if we do get into government the situation economically is not going to be a great one and we have to prioritise.”
Labour’s deputy leader added while she would “love to” go further it was not possible and the current policy was “the right thing to do”.
Drawing on her own experience as a child who received free meals, Rayner said it showed breakfast for children was the most important meal to focus on.
"For the first half of my day I was not looking for education. I was looking how do I get to dinner and what will I be eating," she said.
"My lessons before my school dinner I was basically not with it, because I’m hungry and I wasn’t concentrating."
Starmer last week told the BBC “money is a big factor” as to why he could not promise free school meals for all primary school children.