EU equivalent to MATS Pt.1
 

Does anyone know what the EU equivalent of the MATS Pt.1 is ?

Part.ATS?

Which is basically a cut and paste of ICAO Doc4444 with some more provisions.

As Gonzo said, it's Part-ATS but you need to bear in mind that the EU ANSP is then required to develop their local instructions based on the requirements in Part-ATS.
To an extent the MATS Part 1 covers both aspects and it does that both to simplify the task of creating local instructions for the multitude of ANSPs in the UK, and to ensure a degree of commonality amongst those ANSPs.

Thank you both, really helpful.