“It is for the referring court alone to determine whether … [national] rules [which are intended to transpose the provision of Directive 2003/30 and 2003/96 into the domestic legal order] comply with [the] principles of legal certainty and protection of legitimate expectations … the Court, in a reference for a preliminary ruling … being solely competent to provide the national court with all the criteria for the interpretation of Community law which may enable it to determine the issue of compatibility.”
“the principle of legal certainty, the corollary of which is the principle of the protection of legitimate expectations, requires, on the one hand, that rules of law must be clear and precise and, on the other, that their application must be foreseeable by those subject to them.”
“53. It is clear from the Court's settled case-law that any economic operator on whose part the national authorities have promoted reasonable expectations may rely on the principle of the protection of legitimate expectations. However, where a prudent and circumspect economic operator could have foreseen that the adoption of a measure is likely to affect his interests, he cannot plead that principle if the measure is adopted. Furthermore, economic operators are not justified in having a legitimate expectation that an existing situation which is capable of being altered by the national authorities in the exercise of their discretionary power will be maintained (see, to that effect, in particular, Joined Cases C-37/02 and C-38/02 Di LenardoandDilexport [2004] ECR I6911, paragraph 70 and the case-law cited, andCase C-310/04 Spain v Council [2006] ECR I7285, paragraph 81).”
“71. It should be noted that the right to rely on the principle of the protection of legitimate expectations extends to any individual in a situation in which it appears that the Community administration has led him to entertain reasonable expectations (see, to that effect, Case 265/85 Van den Bergh en Jurgens and Van Dijk Food Products (Lopik) v EEC [1987] ECR 1155, paragraph 44, and Joined Cases C-37/02 and C-38/02 Di Lenardo and Dilexport[2004] ECR I-6911 , paragraph 70). 72. In whatever form it is given, information which is precise, unconditional and consistent and comes from authorised and reliable sources constitutes such assurances (seeCase C-537/08 P Kahla Thüringen Porzellan v Commission[2010] ECR I-0000 , paragraph 63). However, a person may not plead breach of that principle unless he has been given precise assurances by the administration (see Joined Cases C-182/03 and C-217/03 Belgium and Forum 187 v Commission[2006] ECR I-5479 , paragraph 147, and judgment of25 October 2007 inCase C-167/06 P Komninou and Others v Commission, paragraph 63)”
“75. The Court has repeatedly held that the right to rely on the principle of the protection of legitimate expectation extends to any person in a situation where an EU authority has caused him or her to have justified expectations. Nevertheless, the right to rely on that principle requires that three conditions be satisfied cumulatively. First, precise, unconditional and consistent assurances originating from authorised and reliable sources must have been given to the person concerned by the EU authorities. Second, those assurances must be such as to give rise to a legitimate expectation on the part of the person to whom they are addressed. Third, the assurances given must be consistent with the applicable rules …”
“62. As regards, first, the principle of protection of legitimate expectations, in accordance with settled case-law, the right to rely on that principle presupposes that precise, unconditional and consistent assurances, originating from authorised, reliable sources, have been given to the person concerned …”
“the prudent and circumspect operator would and should have understood the modelling to have been undertaken, perforce, on the premise of current Government policy, and as it happens then current power prices, with no inferences capable of being drawn one way or another as to the future direction of policy. This was the only honest, straightforward basis on which such modelling could have been undertaken, and that too would and should have been understood.”
"Under the principle of proportionality, the content and form of Union action shall not exceed what is necessary to achieve the objectives of the Treaties."
"Proportionality as a general principle of EU law involves a consideration of two questions: first, whether the measure in question is suitable or appropriate to achieve the aim pursued; and secondly, whether the measure is necessary to achieve that objective, or whether it could be attained by a less onerous method."
“The repeal of legislation from which a taxable person has derived an advantage in paying less tax, without there being any abuse, cannot as such breach a legitimate expectation based on Community law.”