If they fail to set up new salary scales by April next year the authority could face a raft of equal pay claims.

The exercise, estimated to cost up to £52m, will see the pay of more than 30,000 staff regraded.

The council has already forked-out £14.5m compensation to manual workers, many of them are female, such as cooks and cleaners, who have been denied equal pay for years.But they have been warned workers could take further action if pay is not regraded soon.

Coun Tom Burns, cabinet member for organisational development, said: "We will run scores from the evaluation schemes through a computer especially made for this. We hope to have information on new salaries by Christmas.

"We will then check them with trade union involvement. We are not quite sure what the total cost will be but we've put money away for it."

County chief executive Ged Fitzgerald reassured staff after pay cuts for workers elsewhere, such as Preston Council, where some have been left up to £7,000 a year out of pocket after equal pay reviews.

He said: "We will continue to reassure staff. For most of them it's not going to be bad news.When we get into sensitive areas, we need to manage those collectively with the unions and staff concerned."

Unison representative Jim Moodie has said 9,500 staff are ready to make fresh equal pay claims if the authority misses the April deadline.

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