French companies employ French nationals in the UK on French contracts paying French taxation and have been doing so since before Ryanair existed.
French Govt have refused to have to allow the employees of companies like Eurocamp etc be treated as French employees so to limit anything they could be entitled to.
French Govt have also used their own laws to refuse people with people with Internationally recognised Ski qualifications / Equestrian qualificatsions etc etc to set up running their own business in France.
Funny thing about protectionism is that people always dress it up as something else......