(1)    This section applies where a person is convicted of an offence punishable with a custodial sentence other than one—

(a)    fixed by law; or

(b)    falling to be imposed under section 109(2), 110(2) or 111(2) below.

(2)    Subject to subsection (3) below, the court shall not pass a custodial sentence on the offender unless it is of the opinion—

(a)    that the offence, or the combination of the offence and one or more offences associated with it, was so serious that only such a sentence can be justified for the offence; or

(b)    where the offence is a violent or sexual offence, that only such a sentence would be adequate to protect the public from serious harm from him.

(3)    Nothing in subsection (2) above shall prevent the court from passing a custodial sentence on the offender if he fails to express his willingness to comply with—

(a)    a requirement which is proposed by the court to be included in a probation order or supervision order and which requires an expression of such willingness; or

(b)    a requirement which is proposed by the court to be included in a drug treatment and testing order or an order under section 52(4) above (order to provide samples).

(4)    Where a court passes a custodial sentence, it shall—

(a)    in a case not falling within subsection (3) above, state in open court that it is of the opinion that either or both of paragraphs (a) and (b) of subsection (2) above apply and why it is of that opinion; and

(b)    in any case, explain to the offender in open court and in ordinary language why it is passing a custodial sentence on him.

(5)    A magistrates' court shall cause a reason stated by it under subsection (4) above to be specified in the warrant of commitment and to be entered in the register.