Quote : "I think you overstate the case. Your employer does not pay you for days you are on strike, is this then discrimination? "
This will be the exact legal point: the Law specifically warns you that if you go on a legal strike then your Employer has got the perfectly legal option to withdraw your pay, your Employer can also apply the following "the days you took industrial action on will not usually count towards your total length of service with your employer".
All the rest "in theory" cannot be modified: for example your rank, your salary, your perks. This is the theory behind it.
This was the original intention behind the Law: the practical protection of a legal striker. You cannot have at the same time a legal right on one side and a legal punishment/retaliation versus this same right on the other side....unless the same Law allows it (as deduction of pay)
Obviously a Judge should always give priority to the real intention of the Law when something it is not black and white.
If then the politicians are not happy with the present Law they will have to change it but a Judge should never take a political decision.
We will see.