“…108 Another critical case which builds on the Rottmann line of reasoning is Ruiz Zambrano.109 This case dealt with the decision of the Belgian authorities to deprive the residency and working rights of Mr Ruiz Zambrano, a Colombian national and parent of two children born in Belgium.110 The ecj insisted on the applicability of the case under EU law, despite the absence of crossborder movement, because Mr Zambrano's children were Union citizens and would be deprived of 'the genuine enjoyment of the substance of [their] rights'111 if forced to move outside the territory of the Union.112 Unfortunately, in following cases the Court adopted a more restrictive approach to situations which potentially deprive individuals of the substance of their Union citizenship rights,113 by qualifying the ruling in Ruiz Zambrano as an exceptional case.114 In the recent case of Tjebbes,115despite the effort to follow the principles established in previous case law on EU citizenship, the Court ruled that a measure revoking Dutch and EU citizenship of Dutch nationals, who possess another nationality and who resided outside the Union for more than ten consecutive years, without renewing their passport within that period, is compatible with EU law as long as the proportionality test is performed by the national authorities and courts.116 The vagueness and the passing manner by which the principles of EU citizenship have been applied by the Court, resulted in a missed opportunity to clarify and strengthen the already established principles on EU citizenship.117 Notwithstanding that, the formula of 'substance of rights' established in Ruiz Zambrano, though uncertain, remains promising118 and is regarded as a stepping stone on the way to shaping the material scope of Union law by defending the future ability of individuals to enjoy their EU rights. 119 The judgments in Micheletti, Rottmann and Ruiz Zambrano pave the way towards a better understanding of the relationship between national and Union citizenship.120 With the expansion of the scope of EU citizenship ratione materiae, the requirement of cross-border movement is proven illogical121 in a 'Union without borders' and contrary to the spirit of European integration.122 In the current context, three conclusions can be drawn which will provide guidance in the assessment of the Cyprus Programme. Firstly, Member State nationality must be recognised and respected by all Member States (including the Member State issuing the nationality),123 regardless the mode of naturalisation.…”