international agreements and future proposals come from NATS and not from the regulatory authority.
But that's the way it's supposed to be. CAA is supposed to REGULATE the proposals and agreements (amongst other things).
It does this mainly by checking that NATS' own SMS is working properly (ANSPs are Required to have some form of accountable Safety Management System) and that NATS operates within the Terms of it's licence.
CAA SRG now work in a similar fashion to what used to be CAA Flight Operations Inspectorate, doing for ANSPs what FOI does / did for airlines.
I think....
rgds BEX