The UK CAA has no power to 'accept' or 'reject' an examiner who holds a valid examiner certificate from another EU state and has completed the on-line briefing. All such an examiner needs to do is to follow the published procedure to be 'designated' for the skill test.
There are an increasing number of ATOs now looking to move their principal place of business across the Channel in search of a cheaper and more efficient approvals system whilst retaining their existing facilities as 'alternative bases'. Would the last one to leave the UK please turn off the lights!