"No" to imprisonment of illegal immigrants, El Dridi, C-61/11 PPU

In case El Dridi, C-61/11 PPU, given the status of urgency, the ECJ declared the imprisonment of an illegal immigrant for 1 year due to failure to leave the Italian territory, a measure ordered by the national authorities, contrary to the principle of compliance with the Union law (Article 4(3) TEU, § 56), since the Directive 2008/115 subjects coercive measures to the principles of proportionality and effectiveness (§ 57).

An extremely interesting part of the judgment is § 61 where the CEJ says two things:

1) The national Courts must refuse to apply the national law contrary to the Union law.
2) A retroactive application of a more lenient penalty is a part of the constitutional traditions common to the Member States.