These Regulations are made in exercise of the powers conferred by sections 8(1), 23(1) and (6) and 24(3) of, and paragraph 21(b) of Schedule 7 to, the European Union (Withdrawal) Act 2018 (c. 16).
Link: The European Parliamentary Elections Etc. (Repeal, Revocation, Amendment and Saving Provisions) (United Kingdom and Gibraltar) (EU Exit) Regulations 2018
Source: Legislation .gov.uk