Major Labour donor Dale Vince says he wants to talk to the new government about scrapping compulsory meat and dairy in school meals in England.
The green entrepreneur, who has donated more than £5m to Labour, says vegan meals are healthier and better for the environment.
He is campaigning for an end to all farming of animals, which he says is now the biggest driver of the climate crisis.
He told a fringe meeting at Labour’s conference that his company, Devil’s Kitchen, already supplies vegan food to “one in four” primary schools.
But he added: “There are schools which want to go further. They don’t want meat and dairy on the menu perhaps every day of the week or even at all.
“But it is the law of the land. I am hoping to have a conversation with the new government to encourage them to change the law.”
Government guidance issued to schools in England says they must serve a “wide range of foods across the week”.
This must include fresh fruit and vegetables, some milk and dairy and “a portion of meat or poultry on three or more days each week”.
Mr Vince said it was now clear that a vegan diet was healthier than eating meat and dairy products, adding: “We shouldn’t be forcing these unhealthy products on to our kids.”
He told the meeting he also planned to talk to the education secretary about incorporating “climate and sustainability” into the primary school curriculum.
He denied he was against farmers, insisting that he did not want to kill the industry but allow it to be “reborn”.
“[Farmers] have to be part of the move to net zero, they have to move away from agriculture, we know that the science tells us that – and they already grow grass to feed to animals.”
Mr Vince has donated more than £5m to Labour through his company Ecotricity since Sir Keir Starmer became leader in 2020.
Asked after the meeting if he planned to make further donations, he said: “It’s not the kind of thing I have a plan for. I just do it when I can and when I think they need it, which is usually when there is an election on.”
The businessman said he had stopped funding activist group Just Stop Oil, after Sir Keir came under attack over it.
“I eventually felt it was unhelpful, which was why I stopped funding Just Stop Oil and began focusing on stopping the Tories,” he said.