"We have men who want to live as women, women who want to live as men and personnel who do not identify with any gender.

"The view was we need a uniform policy to cut through all of that and say there is one uniform for everyone and that’s that."

Female recruits were first allowed to wear trousers on parade 16 years ago, in an overhaul of uniform requirements designed to end complaints about ill-fitting, poor quality outfits.

Women can serve in all roles across the RAF, other than as Regiment Officers or Regiment Gunners.

In 2015, the RAF was named one of the top 50 employers for women, who make up around 14 per cent of its personnel, more than the proportion in the Army or Royal Navy.