Female staff’s hourly pay is on average 67% lower than men’s and only 3% of staff in its highest-earning quartile are women.

Under new legislation, all private companies with more than 250 employees must reveal the difference in pay between men and women by Wednesday (April 4).

Ryanair said: “Because the majority of our UK pilots are male, on average, bonus payments to male employees are 20.6% higher than those paid to female employees (mostly cabin crew).

“The median bonus paid to male employees is 3.4% higher than the median bonus paid to female employees.”

The report analysed the pay of 1,182 UK-based staff members belonging to the Irish carrier.

According to the study, Ryanair employees 554 pilots - eight of which are female - and 405 female cabin crew staff compared with 181 male counterparts.

The carrier added: “In Ryanair’s case, our management and administration are based largely in Ireland, so the vast majority of our UK-based colleagues are pilots or cabin crew.

“It is a feature of the aviation industry that more males than females choose to enter the pilot profession.”

According to the report, 82.8% of female staff in the UK receive bonus pay compared to 27.8% of men.