“…Give that neither the Treaty on European Union (TEU) nor the TFEU include a legal definition of Solidarity, 36 but in such cases, talk about spirit of Solidarity, "the European integration process was, however, rapidly constitutionalised, especially after the entry into force of the Treaty of Rome 37 , and under the decisive contribution of the case-law of the Court of Justice of the European Union (CJEU)". 38 On the Judgment Les Verts Case 294/83, 23 April 1986, 39 the European integration process, the CJEU recognised and emphasized that there is a principle of Solidarity between Member States: "the European Economic Community is a Community based on the rule of law, inasmuch as neither its Member States nor its institutions can avoid a review of the question whether the measures adopted by them are in conformity with the basic constitutional charter, the Treaty". 40 As well in recent precedent of the CJEU, on Judgment Commission v Poland 41 Advocate-General Eleanor Sharpston, in her Opinion, highlighted "the Schuman Declaration of 9 May 1950 famously recognised that 'Europe will not be made all at once, or according to a single plan.…”