Why would they start bother with rules now ?
If I was them I would, for 2 reasons :
First ecause these are community rules superseeding local laws, and secondly Spain (AENA, Indra etc..) until now wanted to play a leading role in SES/SESAR. If they continue like this they will de facto expell themselves from it.
They can break any labour agreement they want in their Country but going against EU regulations is another mater.