The French government on Sunday accused the Green mayor of Lyon of insulting French butchers and harming the health of children by keeping meat off the menu for school lunches in the city.

Mayor Gregory Doucet defended the decision, saying the idea of having a single menu without meat was to ensure a smooth service at lunchtimes during the social distancing enforced by the Covid-19 crisis.

But the government pounced on the mayor, who was one of a number of Green politicians to win control of major cities in last year's local elections seen as a drubbing for the party of President Emmanuel Macron.

Lyon is also seen by many as the culinary capital of the country, famed for its hearty meat-based cuisine.

"Let's stop putting ideology on our children's plates," Agriculture Minister Julien Denormandie wrote on Twitter.

"Let's just give them what they need to grow well. Meat is part of it," he said, adding that he had asked the region's prefect, the state-appointed top local official, to overrule the move.

Interior Minister Gerald Darmanin said it was an "unacceptable insult" for French farmers and butchers.

"We can see that the moralising and elitist policy of the Greens excludes the popular classes. Many children often only get to eat meat at the school canteen."

Doucet hit back on Twitter, saying that the measure has been taken "solely" due to the health crisis and adding that his right-wing predecessor as mayor Gerard Collomb had taken "exactly the same measure" during the first wave of the pandemic.

He said that the menu - which includes fish and egg products - was "balanced for all our schoolchildren".

Doucet is not the first of the new breed of Green mayors to court controversy.

Last year the new Green mayor of Bordeaux Pierre Hurmic decided to do away with the city's traditional Christmas tree as part of his pro-environment agenda, saying he was "not going to put dead trees in our squares."

And Doucet himself raised eyebrows by saying the most French of sporting events - the Tour de France - was "macho and polluting" and not welcome back in the city as long as it was not "environmentally responsible".