I wish I had an answer to that.
I think it is a problem. Parliament is sovereign and can always repeal a law. I'm not sure there's anything that can be done to fully guarantee it could never be changed.
Short of embedding it in the Constitution and making a constitutional amendment, so that we would have something that looked like the German constitution with an obligation to protect rights and to rehabilitate.... I would love to see that, but I don't think this committee wants to go down that road right now. Short of that, I don't have a solution.