Kerry Jones, whose daughter attends Ysgol Derwen in Higher Kinnerton in Flintshire, North Wales, has branded the scheme as a 'vacuous gesture'.
'Singling out farmers'
According to North Wales Live, Jones said: "I was fuming. It seems the school is just ramming this issue down our throats.
"If it wants to raise awareness of environmental issues, why not have a paper-free Monday or a car-free Monday? Why doesn't it send out emails rather than letters to parents of the school's 220 pupils?
"It seems people always want to single out farmers."
Jones, who is a farmer herself, said she was 'all for' freedom of speech, but asked: "Why can't [the school] include a meat option and give the children the choice?"
But Flintshire County Council has described the initiative as a success and says it's considering bringing it to other schools in the area.
Claire Homard,Chief Officer for Education and Youth, said: "The headteacher has overseen the development of the leaflets and the menu and is content that this is an example of positive engagement by pupils in issues that they are passionate about.
"The headteacher has also ensured that this initiative is focused on healthy eating and is not being used to actively promote vegetarianism, veganism or a statement against animal cruelty."
The primary school will introduce dishes such as Thai Green Sweet Potato Curry, Potato Focaccia, Butternut Quesadilla and Vegan Shepherd's Pie.