161.Where one piece of legislation amends another by inserting or substituting material, questions may arise as to whether that material is to be interpreted and given effect as part of the legislation which made the amendment, or as part of the legislation into which the material has been inserted. This question may be more significant if different rules of interpretation apply to each piece of legislation (for example, if an Assembly Act or Welsh subordinate instrument to which Part 2 applies amends an Act of the UK Parliament or other legislation to which that Part does not apply).
162.The general position at common law is that the effect of an amendment is to be determined by interpreting the legislation that has been amended, rather than the amending legislation(6). Section 31 makes express provision that is intended to reflect this common law position, for cases where an amendment is made by or to (or by and to) an Assembly Act or a Welsh subordinate instrument.
163.The common law does recognise that in some circumstances it may be necessary to refer to the amending legislation in order to interpret the legislation that it amends, in order to give effect to the intention of the legislator in enacting the amending legislation. In the Act, this is reflected in the fact that the effect of section 32 is subject to any express provision to the contrary or to the context requiring otherwise, by virtue of section 4(1).
164.Section 32 does not have any equivalent in the 1978 Act. However, section 23ZA of the 1978 Act (which is inserted by paragraph 20 of Schedule 8 to the European Union (Withdrawal) Act 2018) provides that most of that Act applies to retained direct EU legislation (other than subordinate legislation) so far as it is amended by domestic legislation including Assembly Acts and subordinate legislation.
See, for example, Inco Europe Ltd v First Choice Distribution [1999] 1 WLR 270, at 272-273.