The new burger, called "the Imposter Burger", will have a fillet made from a meat substitute product, Quorn, instead of its classic chicken breast fillet, the company said in a statement on Thursday.

Plant-based substitutes for meat have been all the rage as more people shift towards vegan or vegetarian diets, amid growing concerns about health risks from eating meat, animal welfare and the environmental hazards of intensive animal farming.

KFC said the burger is being tested in London, Bristol and the Midlands for four weeks before it decides to roll it out nationally.

KFC is hoping to replicate the success that Greggs Plc has witnessed with its wildly popular vegan sausage rolls.

In April, McDonald's Corp started selling burgers in Germany with a patty made from soy and wheat, while Del Taco launched "Beyond Taco" in late April, using U.S.-based Beyond Meat's plant-based protein.

(Reporting by Aishwarya Venugopal in Bengaluru)