Councils have been accused of spending millions of pounds of taxpayers' money on fighting legal battles to stop low paid women winning equal pay.

Unison said local authorities were spending up to £1.3 million each on private barristers' and solicitors' fees and up to £1.2 million on their own staff's time attempting to resist the fight for fair wages.

The union said a survey of 50 authorities in England and Wales found that more than £11.5 million had been spent to "obstruct" equal pay, and claimed that the figure was "the tip of the iceberg".

Using the Freedom of Information Act, Unison said it had discovered that Sandwell council paid out more than £1.3 million to external solicitors and barristers after refusing to negotiate equal pay with the union.

Coventry's bill for external legal help was more than £1.2 million, it was claimed.

Some local authorities had spent huge amounts of money on their in-house legal teams, including Leeds council which had incurred nearly £1.2 million in internal costs and £300,000 to outside lawyers, said Unison.

Sandwell council had spent £124 per female employee resisting equal pay, while the equivalent figure at Rotherham was £115 and in Coventry was £104, Unison claimed.

Unison said the money was being spent despite the introduction of a national "single status" agreement in 1997 which sought to end the gap between the pay of men and women in council jobs, which were either identical or required the same level of expertise or effort.

Dave Prentis, Unison's general secretary, said: "It is a national disgrace that local authorities are spending so much money on fighting to keep women's wages down.

"What a waste of money. Councils are stuffing money into lawyers' pockets to put off the inevitable. Expensive lawyers are raising tiny technical points and fighting issues the councils have already been advised they will lose."