Given that that's out of a population of something like 60 million, I'm sorry to say that the post's title may overstate the situation somewhat.

Also, apparently there are close to 400,000 folks who list their religion as "Jedi Knights", so perhaps once could just as well say "A Corruscant Britain again, like it was a long, long time ago"?

Of course, the Church of England is not the only Protestant denomination in Britain, so I'm pretty sure Roman Catholics are still in the minority.

I think it's important to recognize that those numbers are for observant Romans and Anglicans. Are those who self-identify with a denomination yet attend less regularly that much less significant? (And how might one be an observant Jedi?)

Besides Poles, I wonder whether the liberalization of the Anglican Communion might affect these numbers. IIRC, there was a mass exodus from the CoE to the Roman Church after the former approved the ordination of women. I would expect a steady trickle has continued.