Everywhere? The point of an explicit pre-nuptial is to opt out of what would happen by default. It's opt-out, not opt-in. If you don't have a pre-nup, then you get the standard pre-nup terms which have usually been established over a long period of time, with detailed rules about homes, children, property etc.
Well, that's why I asked my question, ("What are you proposing that's different from that?") because I don't know what he means by mandatory pre-nups, because we already have a mandatory pre-nuptial agreement, and indeed it sometimes kicks in literally before any nuptials.
Clearly they intend something else than a mandatory agreement you sign up for before marraige, because that exists, but they're not really providing any details on how it would differ?