(1) While the agent, nominee or custodian continues to act for the trust, the trustees -

(a) must keep under review the arrangements under which the agent, nominee or custodian acts and how those arrangements are being put into effect,

(b) if circumstances make it appropriate to do so, must consider whether there is a need to exercise any power of intervention that they have, and

(c) if they consider that there is a need to exercise such a power, must do so.

(2) If the agent has been authorised to exercise asset management functions, the duty under subsection (1) includes, in particular -

(a) a duty to consider whether there is any need to revise or replace the policy statement made for the purposes of section 15,

(b) if they consider that there is a need to revise or replace the policy statement, a duty to do so, and

(c) a duty to assess whether the policy statement (as it has effect for the time being) is being complied with.