Greek Police will conduct tougher passport controls at Athens International Airport also for EU citizens coming from or departing for non-Schengen countries. Reason for this is the implementation of EU directive 458/2017, which Greece implements with a delay of two years.
The EU directive does not refer to domestic flights and those to Schengen countries.
In an announcement, Athens International Airport “Eleftherios Venizelos” informs passengers that “as of April 7th, 2019, the Hellenic Police will implement EU Regulation 2017/458 which requires systematic checks against relevant databases, for all European citizens travelling to/from Non-Schengen destinations.”
Does this apply to uk nationals
Why not? The UK isn’t in the Schengen Area.
Since the UK isn’t part of the Schengen Area, if you are flying to or from there then I can’t see why not. See here: