11.

The Court has considered Article 6 of the Habitats Directive on a number of occasions. Most recently, it has summarised its case-law in Sweetman. ( 4 ) It may be helpful to set out here the relevant paragraphs of that judgment: ‘28 Article 6(3) of the Habitats Directive establishes an assessment procedure intended to ensure, by means of a prior examination, that a plan or project not directly connected with or necessary to the management of the site concerned but likely to have a significant effect on it is authorised only to the extent that it will not adversely affect the integrity of that site (Waddenvereniging and Vogelbeschermingsvereniging, [ ( 5 ) ] paragraph 34, and the judgment of 16 February 2012 in Case C‑182/10 Solvay and Others, paragraph 66). 29 That provision thus prescribes two stages. The first, envisaged in the provision’s first sentence, requires the Member States to carry out an appropriate assessment of the implications for a protected site of a plan or project when there is a likelihood that the plan or project will have a significant effect on that site (see, to this effect, Waddenvereniging and Vogelbeschermingsvereniging, paragraphs 41 and 43). 30 Where a plan or project not directly connected with or necessary to the management of a site is likely to undermine the site’s conservation objectives, it must be considered likely to have a significant effect on that site. The assessment of that risk must be made in the light of, in particular, the characteristics and specific environmental conditions of the site concerned by such a plan or project (see, to this effect, Waddenvereniging and Vogelbeschermingsvereniging, paragraph 49). 31 The second stage, which is envisaged in the second sentence of Article 6(3) of the Habitats Directive and occurs following the aforesaid appropriate assessment, allows such a plan or project to be authorised on condition that it will not adversely affect the integrity of the site concerned, subject to the provisions of Article 6(4). 32 In appraising the scope of the expression “adversely affect the integrity of the site” in its overall context, it should be made clear that, as the Advocate General has noted in point 43 of her Opinion, the provisions of Article 6 of the Habitats Directive must be construed as a coherent whole in the light of the conservation objectives pursued by the directive. Indeed, Article 6(2) and Article 6(3) are designed to ensure the same level of protection of natural habitats and habitats of species (see, to this effect, Case C-404/09 Commission v Spain [2011] ECR I-11853, paragraph 142), whilst Article 6(4) merely derogates from the second sentence of Article 6(3). 33 The Court has already held that Article 6(2) of the Habitats Directive makes it possible to comply with the fundamental objective of preservation and protection of the quality of the environment, including the conservation of natural habitats and of wild fauna and flora, and establishes a general obligation of protection consisting in avoiding deterioration as well as disturbance which could have significant effects in the light of the directive’s objectives (Case C-226/08 Stadt Papenburg [2010] ECR I-131, paragraph 49 and the case-law cited). 34 Article 6(4) of the Habitats Directive provides that if, in spite of a negative assessment carried out in accordance with the first sentence of Article 6(3) of the directive, a plan or project must nevertheless be carried out for imperative reasons of overriding public interest, including those of a social or economic nature, and there are no alternative solutions, the Member State is to take all compensatory measures necessary to ensure that the overall coherence of Natura 2000 is protected (see Case C-304/05 Commission v Italy [2007] ECR I-7495, paragraph 81, and Solvay and Others, paragraph 72). 35 As an exception to the authorisation criterion laid down in the second sentence of Article 6(3) of the Habitats Directive, Article 6(4) can apply only after the implications of a plan or project have been analysed in accordance with Article 6(3) (see Solvay and Others, paragraphs 73 and 74). 36 It follows that Article 6(2) to (4) of the Habitats Directive impose upon the Member States a series of specific obligations and procedures designed, as is clear from Article 2(2) of the directive, to maintain, or as the case may be restore, at a favourable conservation status natural habitats and, in particular, special areas of conservation. … 40 Authorisation for a plan or project, as referred to in Article 6(3) of the Habitats Directive, may therefore be given only on condition that the competent authorities – once all aspects of the plan or project have been identified which can, by themselves or in combination with other plans or projects, affect the conservation objectives of the site concerned, and in the light of the best scientific knowledge in the field – are certain that the plan or project will not have lasting adverse effects on the integrity of that site. That is so where no reasonable scientific doubt remains as to the absence of such effects (see, to this effect, Case C‑404/09 Commission v Spain, paragraph 99, and Solvay and Others, paragraph 67). 41 It is to be noted that, since the authority must refuse to authorise the plan or project being considered where uncertainty remains as to the absence of adverse effects on the integrity of the site, the authorisation criterion laid down in the second sentence of Article 6(3) of the Habitats Directive integrates the precautionary principle and makes it possible to prevent in an effective manner adverse effects on the integrity of protected sites as a result of the plans or projects being considered. A less stringent authorisation criterion than that in question could not ensure as effectively the fulfilment of the objective of site protection intended under that provision (Waddenvereniging and Vogelbeschermingsvereniging, paragraphs 57 and 58). … 43 The competent national authorities cannot therefore authorise interventions where there is a risk of lasting harm to the ecological characteristics of sites which host priority natural habitat types. That would particularly be so where there is a risk that an intervention of a particular kind will bring about the disappearance or the partial and irreparable destruction of a priority natural habitat type present on the site concerned (see, as regards the disappearance of priority species, Case C‑308/08 Commission v Spain ( 6 ), paragraph 21, and Case C‑404/09 Commission v Spain, paragraph 163). 44 So far as concerns the assessment carried out under Article 6(3) of the Habitats Directive, it should be pointed out that it cannot have lacunae and must contain complete, precise and definitive findings and conclusions capable of removing all reasonable scientific doubt as to the effects of the works proposed on the protected site concerned (see, to this effect, Case C‑404/09 Commission v Spain, paragraph 100 and the case-law cited). … … 46 … If, after an appropriate assessment of a plan or project’s implications for a site, carried out on the basis of the first sentence of Article 6(3) of the Habitats Directive, the competent national authority concludes that that plan or project will lead to the lasting and irreparable loss of the whole or part of a priority natural habitat type whose conservation was the objective that justified the designation of the site concerned as [a site of Community importance], the view should be taken that such a plan or project will adversely affect the integrity of that site. 47 In those circumstances, that plan or project cannot be authorised on the basis of Article 6(3) of the Habitats Directive. Nevertheless, in such a situation, the competent national authority could, where appropriate, grant authorisation under Article 6(4) of the directive, provided that the conditions set out therein are satisfied (see, to this effect, Waddenvereniging and Vogelbeschermingsvereniging, paragraph 60).’