Three judges at Scotland's highest civil court yesterday rejected argument from Scotland's largest council that 2500 claimants were not eligible for substantial pay-outs because their jobs were transferred to the local authority's arms-length external organisations, or aleos.
The judges ruled in favour of female staff, including cleaners, cooks, home helps and others, now working for organisations such as Cordia.
Carol Fox, of Edinburgh-based Fox and Partners lawyers, welcomed the judgement and said they hoped it marks the "closing chapter" in the long-running battle.
Glasgow's legal team had argued that the claimants could no longer compare themselves to male workers who continue to be employed by the council since they now worked for aleos.
The council had deliberately set out to deny responsibility over equal pay, Ms Fox said, but the move had now been rejected by the highest court.
There are two more appeals outstanding but the decision keeps claimants on track in their fight for significant pay-outs.
The 2500 female staff will now join 3000 others taking the council to an employment appeal tribunal (EAT) with a warning from their lawyer the final settlement could be "multi-million."
Ms Fox added: "We are delighted to have yet another decision in support of our claimants. This means that these 2500 claimants who were subject to TUPE (transfer of undertakings, protection of employment) transfers to aleos will join the other 3000 claimants still working for Glasgow and all of our 5500 claimants will proceed to the EAT together.
"This sends out a very important message to public authorities that it is not acceptable to set up complicated organisational structures in order to escape equal pay liability."
She added: "We call upon Glasgow City Council, the largest public authority in Scotland, to re-think their strategy and to finally address gender pay inequality in Glasgow."
Stefan Cross, a Newcastle-based lawyer who has been involved in the fight, said: "This is a very important decision that will provide much-needed protection for public-sector workers in the battle against ever increasing forms of stealth privatisation.
"This isn't just a victory for Glasgow workers but, potentially, all local government and public-sector staff."
Ms Fox called on council bosses in Glasgow to end their objections and agree settlements before 2015, the 10th anniversary of the campaign to end pay inequality for public sector workers.
Glasgow City Council pointed to the outstanding appeals, adding: "The employment tribunal ruled earlier this year that Glasgow City Council's pay and grading structure is valid and not discriminatory."