24.—(1) Subject to paragraph (2), a variation of, or amendment to, the agreement may only be made in the circumstances provided for in Part 8 of Schedule 2.
(2) Paragraph (1) does not prevent a variation of, or amendment to, an agreement in the circumstances provided for in—
(a)regulation 25;
(b)Part 6; and
(c)paragraphs 43(3) and 52 of Schedule 2.