Burger King has launched its first plant-based burger in the UK, but it is not suitable for vegans because of the way it is cooked.

The soy-based version of the chain’s Whopper beefburger will be available in UK restaurants from Monday, but is cooked on the same grill as meat, meaning that many non-meat eaters will refuse to eat it.

Instead, the fast-food chain is aiming the new burger, which it has named the Rebel Whopper, at “flexitarians” – people who eat meat but are reducing their intake of animal products.

Toni Vernelli, international head of communications and marketing at Veganuary, a campaign to encourage people to go meat, dairy and egg-free for the month of January, complimented the burger.

He said that the method of cooking “makes absolutely no difference” to those trying to cut down meat, but could encourage meat-eaters to lower their consumption.

“What does make a big difference to animals and the planet is when non-vegans choose a plant-based menu option, enjoy it and then order it again,” he said. “And that’s exactly who Burger King’s plant-based Whopper is aimed at, flexitarians who want to reduce their meat consumption for health or environmental reasons, or are considering going vegan.”

The Vegan Society says veganism is “a plant-based diet avoiding all animal foods such as meat (including fish, shellfish and insects), dairy, eggs and honey”. This is generally interpreted as also avoiding products that are cooked with meat.

The marketing director of the fast-food chain, Katie Evans, described the product as a “game-changer”.

“We wanted our first plant-based Whopper to replicate the indulgence and flame-grilled taste of the real thing as closely as possible, and we’re thrilled with the result,” she said. “We’re delighted to satisfy the demand for this highly-anticipated product and finally bring the Rebel to the UK.”

The burger, made in conjunction with meat-free food company the Vegetarian Butcher, has tomatoes, lettuce, mayonnaise, ketchup, pickles on a seeded bun, with a patty made from soy – a common meat substitute.

Growing awareness of the impact of meat and dairy production on the climate has contributed to a spike in veganism in recent years, with the UN a long-standing advocate of reducing animal product consumption.

Last year, 250,000 people pledged to go vegan in January, with vegan celebrities including Venus Williams, Zac Efron and Ariana Grande credited with raising the profile of the movement.

The Rebel Whopper launch comes after Greggs’ debut of its vegan steak bake, a meat-substitute version of its popular pastry, in partnership with vegetarian food brand Quorn.

The high street bakery chain experienced a 10% surge in profits in less than two months last year after launching a vegan sausage roll, paving the way for other fast food chains to add a vegan option to their menus.

The sandwich chain Subway has also made attempts to capitalise on a growing trend towards dairy, egg, and meat-free diets, adding a vegan marinara meatball sandwich to its offering , after launching a vegan patty in 2019.