There's no govcloud in the UK; unless there are specific terms then the terms-of-service state that you are licensing either the irish entity or the american entity to have access and dominion of your data.

I had to spend a lot of time writing my privacy policy (perks of being CTO... yay), and part of that privacy policy was an admission that we transfer ownership of data to a US company (by using public cloud) despite using european datacenters.

This is because our agreement is with a US entity.