Criminal Justice Act 2003:
s. 143 Determining the seriousness of an offence
(1) In considering the seriousness of any offence, the court must consider the offender's culpability in committing the offence and any harm which the offence caused, was intended to cause or might foreseeably have caused.
(2) In considering the seriousness of an offence (‘the current offence’) committed by an offender who has one or more previous convictions, the court must treat each previous conviction as an aggravating factor if (in the case of that conviction) the court considers that it can reasonably be so treated having regard, in particular, to:
(a) the nature of the offence to which the conviction relates and its relevance to the current offence, and
(b) the time that has elapsed since the conviction …
s. 144 Reduction in sentences for guilty pleas
(1) In determining what sentence to pass on an offender who has pleaded guilty to an offence in proceedings before that or another court, a court must take into account –
(a) the stage in the proceedings for the offence at which the offender indicated his intention to plead guilty, and
(b) the circumstances in which this indication was given.
(2) In the case of an offence the sentence for which falls to be imposed under subsection (2) of section 110 or 111 of the Sentencing Act, nothing in that subsection prevents the court, after taking into account any matter referred to in subsection (1) of this section, from imposing any sentence which is not less than 80 per cent of that specified in that subsection …