John Selwyn Gummer is not a politician of the last Conservative period for whom I retain a great deal of nostalgia, but his speech (http://www.theyworkforyou.com/debates/?id=2007-02-20a.154.0#g154.1) asking leave to propose a Catholics (Prevention of Discrimination) Bill was accurate, moving and notably less strident, and therefore more powerful, than it might have been.
It won't happen: legislative change would be necessary in more than a dozen countries, and the number of Constitutional Acts which would need amendment is sufficient to tie up Parliament for an entire session. No Government would want either to lose the chance to legislate or to open a Pandora's box of "if that's up for change, what else might be".
This isn't the sort of discrimination that affects us as individuals but as a Community. Even then, let's not pretend that it is an oppression under which we groan.
But tuck it away in the back of your mind, and next time the canvassers come round to solicit your vote, have a bit of fun with them: "what are the candidate's views about repealing the Act of Succession?"