On 12 May 2010, Lords Phillips, Saville, Brown, Mance and Judge will have to apply all of their skills of statutory interpretation to answer a question which should, as a matter of principle, be obvious to every prisoner leaving the dock: how long will I have to be in prison?

Anyone with experience of sentencing for minor offences in the Crown Court, particularly since 5 April 2005 when the gargantuan Criminal Justice Act 2003 came into force, will appreciate the frustrating complexity that can arise in even the simplest of circumstances. The issue in this case is about such a situation, and the interaction between the Criminal Justice Act 1991, and the Criminal Justice Act 2003 in calculating early release dates. It arose in the case of R (Highton) v Governor of HYMOI Lancaster Farms [2007] EWHC 1085 (Admin), but remains problematic.

Ms Noone was sentenced to consecutive sentences of 22 months, 4 months and 1 month and was initially told she was eligible for Home Detention Curfew in January 2008. However, the governor of HMP Drake Hall later informed her that, in accordance with Home Office policy, the correct calculation would result in Home Detention Curfew in April 2008. The difference arose out of difficulty in calculating the relevant period depending on which sentence was “served first”.

For a taste of quite how byzantine the relevant provisions are, the issue, as it was before the Administrative Court, was summarised in this way:

Under the 1991 Act short-term prisoners were released on licence at the half-way point of their sentence. The secretary of state could release a prisoner on a home detention curfew once he had served the requisite term. The maximum length of a home detention curfew was 135 days where the aggregate term exceeded 18 months. Thus someone such as N, who was sentenced to consecutive terms of 27 months, would be required to be released on licence after thirteen-and-a-half months and would be eligible for home detention curfew 135 days before that time. Had the 2003 Act sentencing provisions been brought into force in full, a logical scheme very similar to that operating under the 1991 Act would have come into existence: short and long-term sentences would have been aggregated, and the custodial period would have been the period specified by the judge in relation to the short sentence and the half-way point in relation to the long sentence. The two would have been added together and that would have produced the answer as to when the prisoner was to be released. However, s.244(3)(b), which defined the requisite custodial period, was not in force, so that there was no provision for establishing the point at which a prisoner sentenced to imprisonment for less than 12 months was entitled to be released or eligible for a home detention curfew.

The following comment from Mr Justice Mitting, in the Administrative Court, was endorsed by the Court of Appeal ([2008] EWCA Civ 1097):

“The position at which I have arrived and which I will explain in detail in a moment is one of which I despair. It is simply unacceptable in a society governed by the rule of law for it to be well nigh impossible to discern from statutory provisions what a sentence means in practice. That is the effect here”.

The Ministry of Justice had attempted to remedy the confusion by considering the first sentence imposed by the Court to be the first sentence served, and calculating the custodial period accordingly. But, as the Claimant has pointed out, this policy causes arbitrary results – depending on which of the consecutive sentences happened to be the first from the judge’s lips. Mitting J. also noted that the it was unlikely that Crown Court judges – including Recorders (part-time judges) – would have appreciated the “fiendishly complex” nature of the legislation in this regard.

However, the Court of Appeal, with some hesitation, accepted the Defendant’s submission. By interpreting the judge’s sentence in the way postulated by the Secretary of State’s guidance, it was possible to calculate the appropriate period in every case. This would not create arbitrary results, provided that the sentencing judge appreciated that the order in which the sentences were pronounced would affect the time spent in custody before early release.

Nevertheless, in reaching that conclusion the Court of Appeal made it clear that it did so because that was the proper interpretation of the statutory provisions. The Court of Appeal deprecated the submission that, where the legislation was unclear, the Secretary of State could resolve that confusion by issuing guidance. As Lord Justice Scott Baker put it:

“…absent any power conferred by Parliament, I would regard it as objectionable in a democratic society for the Secretary of State to dictate by policy matters such as eligibility for release on licence or the period of time spent on licence and liable to recall. In short, I do not think the Secretary of State has the power to make a policy statement of this kind”.

In hearing argument tomorrow  the Supreme Court will therefore need to consider the following points:

First, do the statutory provisions clearly give the answer for calculating sentence length, as advocated by the Secretary of State and accepted by the Court of Appeal?

Second, if not, should the Secretary of State be free to fill that void by issuing policy guidance, as submitted by the Secretary of State, but rejected by the Court of Appeal.

Third, if it is not acceptable for the Secretary of State to use guidance to fill statutory lacunae, should the more favourable interpretation of calculating the relevant period, as advocated by the Claimant, be followed?

Given the frustration on this issue expressed thus far by senior judges we, respectfully, wish the Supreme Court the best of luck.