(1)Neither of the following shall apply to tree works which are authorised for the purposes of this section—
(a)an order under section 198(1) of the Town and Country Planning Act 1990 (c. 8) (tree preservation orders), and
(b)section 211(1) and (5) of that Act (preservation of trees in conservation areas).
(2)Tree works are authorised for the purposes of this section if—
(a)they are required by a notice under section 18(1),
(b)they are carried out, for the purposes of or in connection with the construction of the works authorised by this Act, in relation to a tree growing on land within the relevant limits, or
(c)they are carried out in relation to a tree growing on land used for the purposes of or in connection with Crossrail and are necessary to enable the works authorised by this Act to be maintained or for reasons of safety in connection with the operation of any railway used for the purposes of or in connection with Crossrail.
(3)In this section, references to tree works are to works consisting of the removal, topping or lopping of a tree.