Shambala, a family-friendly festival in the Northamptonshire countryside, is to become the UK’s first greenfield festival to go meat- and fish-free. The move is intended to spark a debate over what we eat and how it affects the environment.

Festival organisers made the decision as part of a commitment to reduce the event’s environmental impact, citing research showing the extent to which livestock farming contributes to global greenhouse gas emissions. The festival’s co-founder Sidharth Sharma, who has been a vegetarian most of his life, said people can be an environmental activist, “just by choosing what’s on your plate”.

“We’re not saying that people shouldn’t eat meat but we want to show that on this site we can prove how great eating in a different way can be,” he said.

Food vendors at the festival, which attracts 15,000 people over the August bank holiday weekend, have been selected to showcase the best of vegetarian cooking. These include the award-winning Parsnipship, which will serve Glamorgan crumbles, beetroot bombs and mushroom bourguignon pie, and Happy Maki – which specialises in vegan, sustainable sushi.

The festival will also feature an insect bar to encourage and educate visitors about“the protein of the future”. Entomophagy has long been feted as an environmentally friendly alternative to meat.

“The debates on the meat industry and climate change go hand in hand,” says Sharma. “We’re being pragmatic and using provocation to get the debate going.”

Dairy products will be served at the festival and visitors can bring their own meat to the site if they want to. The festival has produced a detailed FAQ section on its website to manage queries it has received regarding the decision.

Sharma is keen to make it clear that the festival does not have “all the answers” and admits he had concerns that the decision could put people off coming to the festival.

“We were worried how it could impact on ticket sales,” he said. “But we still sold out, like we have done each year and only two people got in touch to ask for their money back as a result of the decision.”

Shambala has been praised by animal rights groups. Elisa Allen, director of Peta UK, said: “Some people and organisations pay lip service to becoming more ‘green’, but as the UN makes clear, a global shift to a vegan lifestyle is necessary if we are to address climate change, and the Shambala festival is doing its part.”

The Vegetarian Society also supported the initiative but was critical of the decision to host an insect bar. Chief executive Lynne Elliot said: “How brilliant that the Shambala festival is going to be meat- and fish-free, but it’s a shame it is serving food made from insects. Insects are still animals. There’s no need to develop a new sector of the food industry – you can already get all the nutrients you need from a vegetarian diet, which is very sound environmentally.”

The decision has been largely well received by festival-goers, according to Sharma, though there has been criticism on social media, with some meat-eaters stating they “now feel unwelcome” and others saying they feel unhappy at being “forced” to conform to the policy.

However for those who don’t eat meat, who commonly find themselves short of choice at festivals, the news has been welcomed.

“Festivals can be a bit frustrating and I can end up eating a pretty monotonous diet,” says Dean Peters, 32, from London, who is attending Shambala this year and is vegan. Also looking forward to the festival is 27-year-old Allon Gould: “I think a festival is the perfect place for people to see how easy and delicious it can be to go vegetarian, or even vegan. When everyone’s doing it, all the meat cravings disappear.”

• This article was amended on 4 August to give the correct capacity of Shambala festival.