Citizenship and Immigration committee  If I understand the question, it's about an opt-in versus an opt-out. Anything can be done with a bill, subject to the will of the committee, the House of Commons and Parliament. There are very few restrictions on legislating retroactively. There are some constitutional restrictions.

Citizenship and Immigration committee  It would be a policy call for this committee and the House of Commons to decide. I would just note that we have to be careful. For example, for the opt-out, one would have to look at the nationality legislation of the other country in question, because there might potentially still be issues of unintended consequences.