The spokesman declined to comment on whether the menu item would go global.
The venture was announced as the British government is pushing to cut the national consumption of excess calories. Public Health England issued guidelines in March with the aim of reducing the calorie count of some popular foods by 20 percent by 2024.
KFC itself has a seven-year initiative to achieve such a cut in the calorie count of its servings in Britain, and said its work on vegetarian “fried chicken” was part of that.
In deciding to experiment with a vegetarian chicken substitute, KFC also seems to be responding to a growing demand for meat-replacement products such as tofu and soy-based burgers and sausages.
American consumers spent $698.6 million on meat substitutes last year, up 25.6 percent from $556.3 million in 2012, according to statistics published by the research firm Euromonitor International.
Demand for meat alternatives has also risen sharply in Britain, with consumers spending $374.1 million in 2017, up 56.2 percent from $239.5 million in 2012.