It's always best to not mention health related issues, because no-one will otherwise be at all willing to take you on, regardless of the good intentions of any law or disability act. That's the real world for you, they really rather quickly act as if you have the plague and you should be shunned if you are prepared to level with them. If you are in a wheelchair, or have to use one, then there's no way of hiding this from them, so you already are in a major disadvantaged position.

I'd try and fight this, with all the means that are within your power. I am not familiar with how the system works in the UK, but I'm sure there's something you can do to fight them?