"Personal scope 1. Without prejudice to Title III, this Part shall apply to the following persons: (a) Union citizens who exercised their right to reside in the United Kingdom in accordance with Union law before the end of the transition period and continue to reside there thereafter; (b) United Kingdom nationals who exercised their right to reside in a Member State in accordance with Union law before the end of the transition period and continue to reside there thereafter; (c) Union citizens who exercised their right as frontier workers in the United Kingdom in accordance with Union law before the end of the transition period and continue to do so thereafter; (d) United Kingdom nationals who exercised their right as frontier workers in one or more Member States in accordance with Union law before the end of the transition period and continue to do so thereafter; (e) family members of the persons referred to in points (a) to (d), provided that they fulfil one of the following conditions: (i) they resided in the host State in accordance with Union law before the end of the transition period and continue to reside there thereafter; (ii) they were directly related to a person referred to in points (a) to (d) and resided outside the host State before the end of the transition period, provided that they fulfil the conditions set out in point (2) of Article 2 of Directive 2004/38/EC at the time they seek residence under this Part in order to join the person referred to in points (a) to (d) of this paragraph; (iii) they were born to, or legally adopted by, persons referred to in points (a) to (d) after the end of the transition period, whether inside or outside the host State, and fulfil the conditions set out in point (2)(c) of Article 2 of Directive 2004/38/EC at the time they seek residence under this Part in order to join the person referred to in points (a) to (d) of this paragraph and fulfil one of the following conditions: — both parents are persons referred to in points (a) to (d); — one parent is a person referred to in points (a) to (d) and the other is a national of the host State; or — one parent is a person referred to in points (a) to (d) and has sole or joint rights of custody of the child, in accordance with the applicable rules of family law of a Member State or of the United Kingdom, including applicable rules of private international law under which rights of custody established under the law of a third State are recognised in the Member State or in the United Kingdom, in particular as regards the best interests of the child, and without prejudice to the normal operation of such applicable rules of private international law; (f) family members who resided in the host State in accordance with Articles 12 and 13, Article 16(2) and Articles 17 and 18 of Directive 2004/38/EC before the end of the transition period and continue to reside there thereafter. 2. Persons falling under points (a) and (b) of Article 3(2) of Directive 2004/38/EC whose residence was facilitated by the host State in accordance with its national legislation before the end of the transition period in accordance with Article 3(2) of that Directive shall retain their right of residence in the host State in accordance with this Part, provided that they continue to reside in the host State thereafter. 3. Paragraph 2 shall also apply to persons falling under points (a) and (b) of Article 3(2) of Directive 2004/38/EC who have applied for facilitation of entry and residence before the end of the transition period, and whose residence is being facilitated by the host State in accordance with its national legislation thereafter. 4. Without prejudice to any right to residence which the persons concerned may have in their own right, the host State shall, in accordance with its national legislation and in accordance with point (b) of Article 3(2) of Directive 2004/38/EC, facilitate entry and residence for the partner with whom the person referred to in points (a) to (d) of paragraph 1 of this Article has a durable relationship, duly attested, where that partner resided outside the host State before the end of the transition period, provided that the relationship was durable before the end of the transition period and continues at the time the partner seeks residence under this Part. 5. In the cases referred to in paragraphs 3 and 4, the host State shall undertake an extensive examination of the personal circumstances of the persons concerned and shall justify any denial of entry or residence to such persons."
"The general principles applicable to the 'in accordance with the law' standard are well-established: see generally per Lord Sumption in Catt, above, [11]-[14]; and in Re Gallagher[2019] 2 WLR 509 at [16] – [31]. In summary, the following points apply. (1) The measure in question (a) must have 'some basis in domestic law' and (b) must be 'compatible with the rule of law', which means that it should comply with the twin requirements of 'accessibility' and 'foreseeability' (Sunday Times v United Kingdom(1979) 2 EHRR 245 ; Sliver v United Kingdom(1983) 5 EHRR 347 ; and Malone v United Kingdom(1985) 7 EHRR 14 ). (2) The legal basis must be 'accessible' to the person concerned, meaning that it must be published and comprehensible, and it must be possible to discover what its provisions are. The measure must also be 'foreseeable' meaning that it must be possible for a person to foresee its consequences for them and it should not 'confer a discretion so broad that its scope is in practice dependent on the will of those who apply it, rather than on the law itself' (Lord Sumption in Re Gallagher, ibid, at [17]). (3) Related to (2), the law must 'afford adequate legal protection against arbitrariness and accordingly indicate with sufficient clarity the scope of discretion conferred on the competent authorities and the manner of its exercise' (S v United Kingdom, above, at [95] and [99]). (4) Where the impugned measure is a discretionary power, (a) what is not required is 'an over-rigid regime which does not contain the flexibility which is needed to avoid an unjustified interference with a fundamental right' and (b) what is required is that 'safeguards should be present in order to guard against overbroad discretion resulting in arbitrary, and thus disproportionate, interference with Convention rights' (per Lord Hughes in Beghal v Director of Public Prosecutions[2016] AC 88 at [31] and [32]). Any exercise of power that is unrestrained by law is not 'in accordance with the law'. (5) The rules governing the scope and application of measures need not be statutory, provided that they operate within a framework of law and that there are effective means of enforcing them (per Lord Sumption in Catt at [11]). (6) The requirement for reasonable predictability does not mean that the law has to codify answers to every possible issue (per Lord Sumption in Catt at [11])."