Without prejudice to the generality of their powers to acquire land by agreement under section 10 (1) (xx) of the [1968 c. 73.] Transport Act 1968 and section 26 of the [1973 c. 26.] Land Compensation Act 1973, the Executive may acquire by agreement any land in their area which in their opinion—
(a)is likely to be required for extension of the tramway system; or
(b)by reason of published proposals indicating that it might be so required, is a hereditament in respect of which a valid blight notice could have been served on them under section 150 or 161 of the [1990 c. 8.] Town and Country Planning Act 1990 if it were land of the description specified in paragraph 21 of Schedule 13 to the said Act of 1990.