1. RYANAIR UK LIMITED
SATELITE 3
LONDON STANSTED AIRPORT
STANSTED
ESSEX
CM24 1RW
El Bunto
I refer to your post, my understanding was that FR created Ryanair UK in the 90s about 1994, to get around the then rules that restricted Ryanair as a non UK airline from operating a UK domestic route with a full aircraft. PIK STN when it first launched was restricted to selling only 50% of the available seats on the aircraft, and setting up Ryanair UK was a bid to circumvent this rule.
Therefore, I am not sure that the UK alone will be able to ultimately stand over this ruling within the context of EU rules.