Matthew Upson has accused Birmingham of 'moving the goal posts' in blocking his move to West Ham during the January transfer window.
Central defender Upson has seen Blues reject two bids - of £4 million and £6 million - from The Hammers during the past fortnight.
The 27-year-old believes City are asking 'silly money' considering he has only 17 months left of his five-and-a-half-year contract.
It follows on from the claims of his agent Barry Neville who says Birmingham have reneged on a verbal agreement to sell Upson if they receive a certain offer.
And Upson is adamant he will reject any offer of a new contract even if Birmingham regain their Barclays Premiership status next season.
Upson said: 'I think the fee that has been offered by West Ham is a realistic offer, a good sum of money, £6million plus bits and pieces, but we have a difference of opinion.
'I will see how it goes over the next three or four days. It is a bit disappointing in that I feel the goal posts are being moved every week if you like.
'I know it has been labelled the silly season but I think Birmingham have had a pretty good offer for me and yet they have decided to decline it.
'I think figures of £8-£10million for me are silly money given I've only got 17 months left on my contract and I've declined any offers of a new contract.
'Will I still be at Birmingham on February 1? I can't answer that. It is that type of situation.
'I don't know if another bid is going to be made. I don't know if Birmingham are going to make a U-turn. I just don't know.
'But if Birmingham go up, I would not think of staying. That would make no difference.'
Upson admitted: 'A move to West Ham is an attractive possibility to me. With the injection of money they've had, in the next couple of years they could really build.
'They've bought some good players in already which is giving them every chance of survival in the Premiership - which I think they will achieve.
'It could be a good club for the next two or three years to go to and watch it build.'
Upson insisted he would not shirk his responsibilities with Birmingham if he is forced to stay.
He said: 'If can't go, I'll give 100%. I am paid to play football and I have my own reputation and I want to play well. I have a lot of respect for my team-mates, for the fans and myself.
'Whatever disagreement I have with the club, I have my team-mates and a stadium full of fans that I have to turn up and do my job for.
'Would I consider a transfer request? That is something that has been thrown at me but it is a difficult thing to do.
'Once you do that, it might stop you playing and I don't want to do that.'