However, just three games into the loan spell, Hughes was forced to return to Wimbledon after a recurrence on an old ankle injury
Hughes thought his move to Blues would still go through after they had secured promotion to the top-flight, but when his advisors contacted Blues officials, they were told the deal was no longer in place because he hadn't completed the full loan period.
"I am absolutely disgusted - not so much with Wimbledon, but with Birmingham and the FA,' said Larne-born Hughes, capped over 60 times by his country.
"The whole thing is a joke. I had an agreement with Birmingham and they are refusing to honour it and the FA just seem to have washed their hands of the situation. "I am 31-years-old and until this matter is sorted out, I can't play for anyone. It's not just about money, a footballer's career is a finite one - and I will never get this time back. "Would this have been allowed to happen if I had been a high-profile player with someone like Arsenal or Manchester United? I don't think so. "The irony is that I thought Wimbledon had more of a chance of being promoted than Birmingham, so I wasn't that keen to go. But Steve Bruce persuaded me otherwise and the promise of a contract if they did go up clinched the deal. "What Birmingham are saying is bizarre - it's a ridiculous excuse, yet no-one seems big enough or brave enough to do something about it."
"Birmingham have totally messed up my career," he added. "It is totally unacceptable that a football club can do this to someone and no-one can stop it from happening. "I was prepared for it to take a month or six weeks for it to be sorted out but I could never have imagined that we would get to January and it would still be dragging on. It just appears the FA aren't interested. "We all know what the financial situation in football is like now after the ITV Digital problems and it is so frustrating that we are now in January, when clubs finally have the chance to bring players in, and I am still sat here doing nothing.
"The whole thing is a complete nightmare."
Hughes is currently training on his own after Wimbledon told him he could no longer train with them fearing it would jeopardise their case when it was eventually heard.