Just a quick thought, but perhaps the Republic of Ireland could also be in on the deal, after all, they share a language and are as similar in culture as anyone else in this Union.

I suppose the population might not particularly like the idea of union with Britain again, but I can't think they'd dislike it anymore than the old colonies, and so long as all the nations were given equal power I can't see how any could oppose a union that would benefit all parties considerably.