A Labour-led council in the Prime Minister's constituency is expected to fall in line with seven other local authorities which have already been persuaded to go vegan.
A report commissioned by north London's Camden Council found that a 100 per cent plant-based catering regime was "in line" with its "food mission", environmental group Plant Based Councils said.
The group expects plans to be formally incorporated next year, meaning only "plant-based food catering" would be offered at "all internal council-run events and meetings".
"This is a historic win for climate action, public health, and the community," the environmental group stated.
"This decision follows a sustained campaign by local grassroots activists from Plant-Based Councils asking the council to align its food policy with its climate commitments."
While there is no expectation that Camden resident or workers at the council would be banned from eating meat, critics have claimed the council is "wasting vital time and resources ramming through a draconian ban on meat and dairy".
Countryside Alliance External Affairs Director Mo Metcalf-Fisher said Camden Council "should instead be supporting our British farmers".
"(They) produce some of the most sustainable food in the world, regardless of whether its meat, dairy or vegetables," he said.
PLANT-BASED COUNCILS
|Plant-Based Councils’ Camden team and supporters outside Camden Townhall
The campaign group has said Camden was the third London borough to take "this transformative step towards plant-based catering" - following in the footsteps of Lewisham and Hackney.
However, other local authorities outside of London have also made the move.
Oxfordshire County Council, Calderdale and Exeter City Council all committed to 100 per cent plant-based internal catering.
However, following Camden's announcement, medical doctor and Camden Plant-Based Council members, Kush Naker, said it was a "huge moment" for the borough.
PLANT-BASED COUNCILS
|Kush Naker presenting to Camden Council
"Not just for Camden, but for climate action in the UK," Naker said.
"We're thrilled that our council has listened to the science and the local community and shown real leadership."
He said the policy was not about telling people what to eat, but "ensuring that our public institutions reflect the urgent need to shift toward sustainable, inclusive, and compassionate food systems".
Now that the group has got their way with Camden Council, they said they hope the "bold move will inspire other councils across London and the London Assembly to follow suit".
GB News | Mo Metcalf-Fisher
"As the capital of the UK, London should lead the way for others to do the same," the group said.
"The councillors also expressed support for the Plants First Healthcare campaign and committed to writing to local hospitals and healthcare providers, encouraging them to deliver 'plant-based by default' catering to patients and visitors at their sites."
However, the Countryside Alliance has claimed 10 councils rejected "compulsory veganism" in a bid to promote the importance of shopping locally and supporting UK farmers.
Suffolk, Cornwall, Portsmouth, Fenland, Peterborough, the Highlands, Dorset, Wilshire, Staffordshire Moorlands and Rutland have signed up to the opposing campaign.
Metcalf-Fisher said there were questions for Starmer and MPs on whether other Labour councils would be going vegan as well.