23.—(1) The undertaker may acquire compulsorily so much of, or such rights in, the subsoil of the land referred to in paragraph (1) of article 18 (compulsory acquisition of land) or article 20 (compulsory acquisition of rights) as may be required for any purpose for which that land may be acquired under that provision instead of acquiring the whole of the land.
(2) Where the undertaker acquires any part of, or rights in, the subsoil of land, the undertaker is not required to acquire an interest in any other part of the land.
(3) The following do not apply in connection with the exercise of the power under paragraph (1) in relation to subsoil only—
(a)Schedule 2A (counter-notice requiring purchase of land not in notice to treat) to the 1965 Act; and
(b)Schedule A1 (counter-notice requiring purchase of land not in general vesting declaration) to the 1981 Act; and
(c)section 153(4A) (blighted land: proposed acquisition of part interest; material detriment test) of the 1990 Act.
(4) Paragraphs (2) and (3) are to be disregarded where the undertaker acquires a cellar, vault, arch or other construction forming part of a building.