The legislation is dynamic action and phases, pre-legislative, legislative and post-legislative. I have studied post-legislative doctrine, legal norm control, typical to the European Union legal order. I have studied more closer the art. 263 TFEU and 267b TFEU of the Union and relevant case law (Digital Rights, Vodafone etc.). As conclusions the most important aspect is not the legal grounds, how Court annuls Union legislation, but the arguments and reasoning of the Court in the Union norm control case law. The Court is not taking its position only legally or legistic-linguistic way, but it is also tackling factual aspects of legislation, produced through ex-ante evaluations. The Court faces the empirical world, epistemic uncertainty as Robert Alexy and Matthias Klatt have written. My argument is that norm control of legislation is one important source of legislation – the doubts relating to democracy principle must be seen from the point of view of modern rule of law demands.