The GMB Union has issued the warning to the City Council and claims Birmingham 2022 could face "strike disruption" if the situation is not resolved.

Birmingham is scheduled to stage the Commonwealth Games in fewer than three months' time.

It will be the biggest multi-sport event to be held in England since the London 2012 Olympics and Paralympics.

According to the GMB Union, staff have lodged claims relating to "systematic inequality" in pay faced by female Council workers.

The union said it had called on its members not to sign any settlement agreement after claiming that "significant new information emerged surrounding problems with the Council's job evaluation scheme".

"The Commonwealth Games are a huge opportunity for our city to showcase the best of Birmingham, but risks being overshadowed by the brewing equal pay crisis faced by our members," said Michelle McCrossen, regional organiser for the GMB.

"GMB won't stand by as our members' concerns are ignored, we're 100 per cent committed to fighting for a solution.

"The eyes of the millions worldwide will soon be on our city and we're urging the Council to act now before our members are forced to consider taking action in the interests of their pay and rights at work.  

"This is a matter of basic justice; women workers are being consistently underpaid by Birmingham City Council and GMB won't stand by and let that be forgotten."

The GMB Union said its 7,000 members at the City Council work in services across the city, including refuse, adult social care, education and administration.

Should strike action take place, it is unclear which services at Birmingham 2022 could be impacted.

"There have been historic issues around equal pay, well documented, and yet despite our efforts new problems arise," said GMB senior organiser Stuart Richards in a report by the Birmingham Mail.

"City Council members are also increasingly frustrated that the focus of the leadership of the Council appears to be on the Games at the expense of serious issues.

"This issue has now dragged on.

"The job evaluation scheme itself is fairly good but they have allowed individual areas of the council to bend those agreements.

"It is great that activist members in one area of the Council can get changes to work patterns agreed, but that then needs to be applied fairly to everyone."

In response to the warning over strike action, a spokesperson from Birmingham City Council told insidethegames: "The Council is committed to treating all members of staff fairly and committed to resolving any outstanding matters around equal pay once and for all and encourage any trade union concerns to be discussed and explored with the Council."

The Birmingham 2022 Commonwealth Games are set to be held from July 28 to August 8.