20. Where the trust-property consists of money and cannot be applied immediately or at an early date to the purposes of the trust, the trustee is bound (subject to any direction contained in the instrument of trust) to invest the money on the following securities, and on no others:-(a) in promissory notes, debentures, stock or other securities ¹[of the Government]:Provided that securities, both the principal whereof and the interest whereon shall have been fully and un-conditionally guaranteed by ²[the] Government, shall be deemed, for the purposes of this clause, to be securities of ³[the] Government; ⁴[* * *] ⁵[(c) in stock or debentures of, or shares in, Companies the interest whereon shall have been guaranteed by the Government: (d) in debenture or other securities for money issued under the authority of any Bangladesh Act, or on behalf of any municipal body or port trust or city improvement trust: ](e) on a first mortgage of immoveable property situate in ⁶[Bangladesh]: Provided that the property is not a leasehold for a term of years and that the value of the property exceeds by one-third, or, if consisting of buildings, exceeds by one-half, the mortgage-money; or(f) on any other security expressly authorised by the instrument of trust, or by any rule which the ⁷[Supreme Court] may from time to time prescribe in this behalf: Provided that, where there is a person competent to contract and entitled in possession to receive the income of the trust-property for his life, or for any greater estate, no investment on any security mentioned or referred to in clauses (d), (e), and (f) shall be made without his consent in writing.