Thousands of female council workers who had been denied access to compensation over a row about equal pay could now receive a payout after a ruling in the High Court.

The ruling has meant 174 women workers at Birmingham City Council, including cleaners, dinner ladies and care home staff, will be given the right to make equal pay claims even though they complained about unfair pay packets more than six months after leaving their job.

The ruling reopens the prospect for thousands of women who retired or changed jobs, until now denied the right to make claims because they had left it too long, to make claims. It also vastly increases the equal pay liabilities of councils, health trusts and other public sector organisations facing equal pay challenges.

Councils have already paid out millions to women care workers, dinner ladies and cleaners who courts ruled had not been paid the same as comparable male dominated jobs such as dustmen, road workers and street sweepers.

The council argued that claims should go through an employment tribunal, for which there is a six month limit, but the judge, Colin Edelman QC, ruled that the High Court does have jurisdiction and that a six-year limit should apply.

Paul Savage, of equal pay firm Action for Equality, said: “There are thousands of workers who missed out on equal pay compensation because they were out of time. This will open the floodgates.

“We will be talking to them about their cases in the New Year.”

A spokesman for the city council said that it would be seeking leave to appeal through the courts.

In another case the local authority has won an employment tribunal against the leading public sector union Unison over claims of unfair dismissal.

The union claimed that staff whose contracts were changed in 2008 as part of a pay and grading review were unfairly dismissed, but the tribunal ruled they had been adequately consulted.

Coun Alan Rudge, cabinet member for equalities and human resources, said: “The city council has always maintained that its pay and grading review was fair and that unions and employees alike were appropriately consulted throughout.

“The council is at a complete loss in seeking to understand why the unions have pursued claims without merit against the council at huge cost to the public purse, when they are aware that the council has an expectation to deliver huge efficiency savings over the next two to three years.”