The British Nationality Act 1981 (Immigration Rules Appendix EU) (Amendment) Regulations 2021
These Regulations are made in exercise of the powers conferred by section 5(1) of the Immigration and Social Security Co-ordination (EU Withdrawal) Act 2020 (c. 20), in order to make provision in consequence of or in connection with Part 1 of that Act, which (amongst other things) makes provision to end rights to free movement under retained EU law.