As a Briton I'll tell you that it is nothing like that high in any real sense. Church attendance is below 5% if memory serves. I know 2 families only who attend church on Sundays and even there 1 partner is going on sufferance. Lots of people who don't believe anything in particular will still tell a pollster that they are C of E, and fill in the religion question on official forms with C of E. My wife does so for example, and she is a more militant atheist than I am.
Literal US style creationism is invisible here outside the muslim population. I doubt that even the C of E priests and bishops believe the Old Testament. Does it sound like Hell on Earth to you?
The church here is entirely identified with socialist and liberal policy (just like our current government). But Christianity has almost no support, to the point where the Church Commissionners can run fewer and fewer churches and each priest serves several churches to save money. That is where compulsory religious education in schools gets you. We have a church established with the state and 2 hours a week compulsory RE in state-run schools, and 2-3x weekly compulsory religious assemblies in most schools, and most people leave school believing not a word of it.
Oh, that the US can become more like England. We were wrong to ever want to break away to begin with.