(1) Subject to subsections (2) to (4), any provision contained in a trust deed for securing an issue of debentures, or in any contract with the holders of debentures secured by a trust deed, shall be void in so far as it would have the effect of exempting a trustee thereof from or indemnifying him against liability for breach of trust where he fails to show the degree of care and diligence required of him as trustee, having regard to the provisions of the trust deed conferring on him any powers, authorities or discretions.
(2) Subsection (1) shall not invalidate -
(a) any release otherwise validly given in respect of anything done or omitted to be done by a trustee before the giving of the release; or
(b) any provision enabling such a release to be given -
(i) on the agreement thereto of a majority of not less than three-fourths in value of the debenture holders present and voting in person or, where proxies are permitted, by proxy at a meeting summoned for the purpose, and
(ii) e