So as certificates for ATM/ANS providers (including NERL) will no longer be recognised by EASA, then I assume no EU operators will be allowed to enter UK airspace, including flights between mainland Europe and North America? That won't be down to the UK refusing overflight clearance which, as has been pointed out earlier, is not possible, but because EASA won't allow EU operators to fly into airspace that is controlled by an entity that doesn't hold a valid EASA authorisation.
Yeah, I can just see that happening!
I suspect it isn't just the UK that 'wants to have its cake and eat it too'