24.—(1) In this Part “market rent”, in relation to the tenancy of a dwelling, means the rent which a willing tenant not already in occupation would give and a willing landlord would take for the dwelling, in each case on the basis of vacant possession being given, and having regard to—

(a) the other terms of the tenancy, and

(b) the letting values of dwellings of a similar size, type and character to the dwelling and situated in a comparable area to that in which it is situated.

(2) References in this Part to a review of a rent include references to—

(a) any procedure (however it is described) for determining whether, and to what extent, a reduction or increase in the amount of the rent for the time being payable under the tenancy concerned ought to have effect, and

(b) the effect of the operation of a provision of a lease or tenancy agreement providing that, by reference to any formula, happening of any event or other matter whatsoever (and whether any act, decision or exercise of discretion on the part of any person is involved or not), such a reduction or increase shall have effect,

and, in the case of a provision of the kind referred to in paragraph (b), any prohibition under this Part on a review of rent occurring is to be read as a prohibition on the provision operating to have the foregoing effect.

(3) References in this Part to the setting of a rent are references to the oral agreeing of the rent or to its being provided for in a lease or tenancy agreement or, in the context of a review of rent—

(a) the oral agreeing of the rent,

(b) the oral or written notification of the rent, or

(c) in the case of a provision of the kind referred to in subsection (2)(b), the rent being set by virtue of the operation of that provision.