“Article 20 1. Citizenship of the European Union is hereby established. Every person holding the nationality of a Member State shall be a citizen of the Union. Citizenship of the Union shall be additional to and not replace national citizenship. 2. Citizens of the Union shall enjoy the rights and be subject to the duties provided for in the Treaties. They shall have, inter alia: a). The right to move and reside freely within the territory of the Member States…. Article 21 1. Every citizen of the Union shall have the right to move and reside freely within the territory of the Member States, subject to the limitations and conditions laid down in the Treaties and by the measures adopted to give them effect.”
“…a right to reside…which exists by virtue of… (e) Article 20 of the Treaty on the Functioning of the European Union (in a case where the right to reside arises because a British citizen would otherwise be deprived of the genuine enjoyment of the substance of their rights as a European Union citizen).”
“Article 18 TFEU Within the scope of application of the Treaties, and without prejudice to any special provisions contained therein, any discrimination on grounds of nationality shall be prohibited. The European Parliament and the Council, acting in accordance with the ordinary legislative procedure, may adopt rules designed to prohibit such discrimination. Article 21 of the EU Charter: non-discrimination1. Any discrimination based on any ground such as sex, race, colour, ethnic or social origin, genetic features, language, religion or belief, political or any other opinion, membership of a national minority, property, birth, disability, age or sexual orientation shall be prohibited. 2. Within the scope of application of the Treaty establishing the European Community and of the Treaty on European Union, and without prejudice to the special provisions of those Treaties, any discrimination on grounds of nationality shall be prohibited.”
“provided that such refusal does not lead, for the Union citizen concerned, to the denial of the genuine enjoyment of the substance of his status of Union citizenship right.”