Ottergirl:
What you say maybe correct BUT and a BIG BUT staff travel is a PERK and can be withdrawn at any time regardless of any reason - so how that can stand up in a court of law beats me.
If you read your contract of employment there will be a clause in their stating exactly that.
Your staff travel can be withdrawn for a variety of reasons, for example if you continually arrive back late from a holiday on a staff ticket without back-up tickets you can be warned that staff travel will be withdrawn - this has happened to me. If you are off sick you are not allowed to travel on staff tickets either 'APPARENTLY'.
The point is CC knew BEFORE they went on strike that staff travel would be rescinded but they went ahead anyway with full knowledge. If it had been taken away AFTER the strike then yes I would certainly think they had a case but in a court of law a 'PERK' is at the discretion of the company and is not contractual.