31.Section 6 provides that the new general power of investment (defined in section 3(2)) is a default provision.  It specifies that subject to the provisions of section 7 relating to trusts in existence when the Act is brought into force, the new power will be available to all trustees in addition to any limited express power of investment vested in them, but subject to any limitation imposed by the trust instrument or by primary or subordinate legislation (section 6(1)).  This provision follows the precedent of section 69(2) of the Trustee Act 1925 in relation to the powers conferred by that Act.
32.“Subordinate legislation” is defined in section 6(3) by reference to the Interpretation Act 1978 to mean Orders in Council, orders, rules, regulations, schemes, warrants, byelaws and other instruments made or to be made under any Act (Interpretation Act 1978 section 21(1)).
Commentary on Sections Part II: Investment Section 6: Restriction or exclusions of this part etc.