The Secretary of State may require a police authority to exercise their power under Part I of this Act to call upon the chief constable to retire in the interests of efficiency F1or effectiveness.

Before requiring the exercise of that power or approving the exercise of that or the similar power exercisable with respect to F2an assistant chief constable, the Secretary of State shall give the chief constable F3. . . or assistant chief constable an opportunity to make representations to him and shall consider any representations so made.

Where representations are made under this section the Secretary of State may, and in a case where he proposes to require the exercise of the power mentioned in subsection (1) of this section shall, appoint one or more persons (one at least of whom shall be a person who is not an officer of police or of a Government department) to hold an inquiry and report to him and shall consider any report made under this subsection.

The costs incurred by a chief constable F3. . . or assistant chief constable in respect of an inquiry under this section, taxed in such manner as the Secretary of State may direct, shall be defrayed out of the police fund.