14) However, the referring court takes the view that, even though Paragraph 4(2) UIG requires the competent national authority to accede to Mr Stefan’s request, it is apparent that provision of the data sought would have negative effects on the ability of the lock keeper in question to receive a fair trial within the meaning of Article 6 of the European Convention for the Protection of Human Rights and Fundamental Freedoms, signed at Rome on 4 November 1950, or of the second paragraph of Article 47 of the Charter of Fundamental Rights of the European Union (‘the Charter’).

15) According to that court, since Directive 2003/4 does not oblige Member States to refuse a request for access to environmental information in a case where the disclosure thereof would compromise the ability of any person to receive a fair trial, but merely permits such a refusal in point (c) of the first subparagraph of Article 4(2) thereof, that directive authorises Member States to adopt measures that are at variance with the fundamental rights protected in the European Union, a fact which renders it incompatible with the second paragraph of Article 47 of the Charter.

16) In those circumstances, the Unabhängiger Verwaltungssenat Wien (Vienna Independent Administrative Tribunal) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:

‘1. As regards the validity of [Directive 2003/4]: is [that directive] in every respect compatible with the requirements of the second paragraph of Article 47 of the [Charter]?

2. As regards the interpretation of [Directive 2003/4]: In the event that the Court of Justice affirms the validity of Directive [2003/4] in its entirety or the validity of parts thereof, to what extent and on the basis of what assumptions are the provisions of that directive compatible with the provisions of the [Charter] and the requirements of Article 6 TEU?’

...

25) The French Government’s argument concerning the admissibility of the request for a preliminary ruling rests on the premiss that the disclosure of environmental information, in circumstances such as those in the case in the main proceedings, does not constitute a breach of the right to a fair trial within the meaning of the second paragraph of Article 47 of the Charter.

26) Such a determination, however, comes under the jurisdiction of the referring court. Furthermore, it requires an interpretation of that provision of the Charter, in relation to which that court has not referred questions to the Court of Justice in the context of the present request for a preliminary ruling.

...

29) By its questions, which it is appropriate to examine together, the referring court asks, in essence, whether Directive 2003/4 is valid in the light of Article 6 TEU and the second paragraph of Article 47 of the Charter.

30) In this regard, it must be noted that, under Article 51(1) of the Charter, the fundamental rights guaranteed therein must be respected where national legislation comes within the scope of EU law (see, to that effect, Case C‑617/10 Åkerberg Fransson EU:C:2013:105, paragraph 21).

31) It follows that Member States are required to respect, inter alia, the second paragraph of Article 47 of the Charter when they implement Directive 2003/4.

...

33) By referring to the ability of any person to benefit from the right to receive a fair trial, point (c) of the first subparagraph of Article 4(2) of Directive 2003/4 authorises Member States to provide for an exception to the obligation to disclose environmental information in order, specifically, to allow them, if the circumstances so require, to respect the right to a fair trial laid down in the second paragraph of Article 47 of the Charter.

34) Furthermore, even if a Member State does not provide for such an exception in its legislation intended to transpose Directive 2003/4, although, in order to respect the second paragraph of Article 47 of the Charter, circumstances require it, it must be borne in mind that Member States are, in any event, required to use the margin of appreciation conferred on them by point (c) of the first subparagraph of Article 4(2) of that directive in a manner which is consistent with the requirements flowing from that article of the Charter (see, to that effect, Case C‑540/03 Parliament v Council EU:C:2006:429, paragraph 104).

35) Since all authorities of the Member States, including the administrative and judicial bodies, must ensure the observance of the rules of EU law within their respective spheres of competence, they are, in a case such as that here at issue in the main proceedings, required, if the conditions are fulfilled for application of the second paragraph of Article 47 of the Charter, to ensure compliance with the fundamental right guaranteed by that article (see, to that effect, Case C‑249/11 Byankov EU:C:2012:608, paragraph 64).

36) In those circumstances, an interpretation to the effect that Directive 2003/4 authorises Member States to adopt measures that are incompatible with the second paragraph of Article 47 of the Charter or with Article 6 TEU cannot be accepted. That directive is therefore, on the same basis, not invalid in the light of those two provisions.