If you are returning to your normal job when you actually return from ML then strictly speaking you will not be able to rely on the Regulations because they are allowing you to return to the same job on your return. So unless the reason your job changes after that is because you were of on ML then this is unlikely to be discrimination. It will however be a potential redundancy situation so if you are not offered a suitable alternative position instead you can go for redundancy. If they refuse to consider making you redundant then that is where you will be looking at resigning and claiming constructive dismissal instead.
Hope this clarifies your position?
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