These Regulations are made in the exercise of the powers conferred by section 8(1) of the European Union (Withdrawal) Act 2018 (c. 16) in order to address failures of retained EU law to operate effectively and other deficiencies (in particular under section 8(2) of that Act) arising from the withdrawal of the UK from the European Union.
Link: The Animals (Scientific Procedures) Act 1986 (EU Exit) Regulations 2019
Source: Legislation .gov.uk