Women's earnings in the civil service are a third lower than men's

According to figures revealed in the Office for National Statistics' civil service employment report, in the Attorney General's Departments women earn 28% less than men, in the Treasury their earnings are on average 27% lower and in the Department for International Development the figure is 20%.

Across the civil service the median pay gap between men and women comes in at 15.3% - but in the department for Innovation, Universities and Skills this rises to 25%.

Women make up 29% of full-time civil service staff and the Liberal Democrats are pushing for pay audits so women can compare their salary with male colleagues and demanding ‘no name' application forms to prevent unconscious discrimination.

Liberal Democrat Equalities spokeswoman Lynne Featherstone (pictured) said: "Forty years on from the Equal Pay Act the Government still has not put its house in order.

"Women should not be made to wait another 40 years before they are paid equally. Companies should publish pay audits so discrimination against women in the workplace will finally be stopped."