Civilian workers are paid differently according to where they work

Unison said women carrying out forensic work and other civilian tasks earned 10% less than male colleagues, and holiday entitlement was "inconsistent."

It wants set terms and conditions for all police staff in England and Wales.

The Home Office said it is continuing to "develop workforce reform" within the police service.

Unison criticised the current set-up which allows individual forces to decide how much civilian staff are paid.

'Gender pay gap'

"The service is showing itself to be a dinosaur employer, sticking to its old ways," Ben Priestley, Unison's national officer, said.

"Police officers get a standard holiday allocation wherever they are stationed, but police staff entitlement differs across the country, starting at 22 days.

"The gender pay gap still exists, and in a modern public service this is not acceptable."

Some police officers were given extra money to cope with the standard of living, but this did not apply to civilian staff, he added.

The union's demand follows a pay dispute between civilian staff and Devon and Cornwall Police.

'Workforce reform'

Forensic analysis and other civilian staff at the force's Exeter headquarters walked out in April after it regraded their salaries, resulting in pay cuts of up to �8,000 for some.

The union said it was planning to take on more equal pay claims after seven women working for South Wales Police won a claim for equal pay in January 2004.

A Home Office spokesman said further pay reforms "must support the operational requirements of the service, take account of the changing requirements of police roles and reflect in the right proportion the demands of the role, skills and performance".