We have heard from the former Attorney General and the former Solicitor General, who have great legal expertise. The point that they make is right: this agreement will be legally binding on member states as a matter of international law. First, of course, it has to be agreed, but once it has been agreed, my hon. and learned Friend is absolutely right that it would be irreversible because it could be amended or revoked only if all member states, Britain included, decided to reverse it. Therein lies its irreversibility.