The civil service has been criticised for failing to address equal pay issues amongst its own employees.

Liberal Democrat equalities spokeswoman Lynne Featherstone said the pay gap between male and female civil servants was a "sad reflection" on the state of equal pay in this country.

She made the criticism as she launched her party's policies to tackle the gender pay gap in the wider economy, including renewed calls for mandatory pay audits.

Using Office for National Statistics figures, and weighting the figures by department size, the Lib Dems have calculated that the gender pay gap is as large as 28 per cent in the Attorney General's Office.

At the Treasury it is 27 per cent and at the Department for International Development (DFID) it is 20 per cent, the party says.

The figures do not take into account the grades of employees and are partly because there are so few women in the most senior roles.

Only 31 per cent of full-time equivalent staff in the senior civil service (SCS) are female, and the lower down the grades and the pay scales, the more women there are.

Featherstone commented: “Forty years on from the Equal Pay Act, the government still hasn’t put its own house in order.

“The fact that women make up such a small proportion of full time senior civil servants is very depressing. If the civil service is unable to treat men and women equally, what hope is there for the private sector?

“It is a sad reflection on the state of equal pay in this country that women in some government departments can expect to earn up to 30 per cent less than their male colleagues.

“Women shouldn’t be made to wait another 40 years before they are paid equally. Companies should publish pay audits so that discrimination against women in the workplace will finally be stopped.”

When employee grade is taken into account, and like is compared with like, the pay gap is much lower, but still present. Across the civil service, the pay gap ranges between 4.1 and 5.6 per cent, depending on which grade is examined.

At the Treasury, for example, the highest pay gap - 10 per cent - is at SCS level, dropping down to 4.6 per cent at grades 6 and 7, and 1.3 per cent at senior and higher executive officer level. Female executive officers, administrative officers and administrative assistants in the Treasury are actually paid more, on average, than their male counterparts.

Featherstone's policy proposals, announced on Wednesday, include a "no name" policy for job applications, replacing names with numbers, better career advice to girls and extending the right to request flexible working to all employees, not just parents, in order to reduce the stigma attached to requests.

Featherstone also wants groups to be able to bring representative legal actions, rather than just individual cases, and would like to see ethnic minority women who face what is called "double discrimination" to be able to bring cases on both grounds, rather than having to choose one.

Contrary to the government's stated policy, the Lib Dems have also called for a legal requirement for private sector organisations to publish pay scales and conduct pay audits.

The government's Equality Bill, currently making its way through Parliament, firms with more than 250 employees will be "encouraged" to publish limited details on pay by 2013. If there has been no reduction in the gender pay gap by 2013, the government says it will bring in legislation.