In March and in May 2011 the Supreme Court in Walumba Lumba and Kadian Mighty –v- Secretary of State for the Home Department  and in Shepherd Masimba Kambadzi –v- Secretary of State for the Home Department  the Court endorsed and explained the principles covering the use of powers to detain someone for immigration purposes under Immigration law .
Eight of the nine Supreme Court Judges agreed with the Hardial Singh  decision which set out the principles concerning the use of powers to detain someone for immigration purposes. The principles are that:
1. The Secretary of State must intend to deport the person and can only use the power to detain for that purpose;
2. The Deportee may only be detained for a period that is reasonable in all the circumstances;
3. If before the expiry of the reasonable period, it becomes apparent that the Secretary of State will not be able to effect deportation within a reasonable period, he should not seek to exercise the power of detention;
4. The Secretary of State should act with all diligence and expedition to effect removal.
These principles apply whether the person is to be removed or deported. However, the Hardial Singh principle cited above will not apply to all people being detained for immigration purposes. They would not apply for Immigration Officers who detain someone at the port of entry to the UK to investigate whether the person is permitted to enter the UK or when an asylum seeker’s claim is being dealt with in the detained fast track.
The Supreme Court considered that in a case of someone who is facing deportation having been convicted of a criminal offence in the UK the risk of re-offending is a relevant factor to consider in relation to the use of immigration detention. I.e. the Immigration Officer should take into account the likelihood of re-offending and the seriousness of any re-offending.
Furthermore the Supreme Court considered that in the case of someone facing deportation or removal, outstanding legal challenges under Immigration law are relevant factors to consider in relation to the use of immigration detention ,for example if the Immigration lawyers are making representations to the UK Border Agency , or an appeal to the First Tier Tribunal or an application for Judicial Review to the Administrative Court has been made. It will be necessary to consider the prospects of any legal challenge succeeding. In short in assessing what period or length of detention is reasonable in all the circumstances, the Supreme Court has concluded that an outstanding legal challenge, particularly where there is some prospect of success, may be a factor indicating that a shorter period is reasonable.
Finally, the Supreme Court also considered that in a case of someone facing deportation a refusal to make a voluntary departure may have little or no relevance to the use of immigration detention.
The Supreme Court also considered the circumstances in which a failure by the UK Border Agency to follow its published policy under Immigration Law may make someone’s detention unlawful. A failure without a good reason by the UK Border Agency to follow a published policy was capable of making someone’s detention unlawful. For example if the UK Border Agency fails to conduct regular reviews of a detention as required by its published policy.