Section 39 of the Constitutional Reform Act 2005 provides for the appointment of a Supplementary Panel, upon which the Court can call when additional judges are needed to form a panel of the requisite number.
Those appointed to the Supplementary Panel have to be appointed while still in office or within two years of ceasing to hold office.
A Supplementary Panel member ceases to be on the panel after five years of ceasing to hold a qualifying office or (if earlier) when 75.
Members of the supplementary panel are not Justices of the court. They can only sit on the court in the event that they are requested to do so by the President.
The Supreme Court's Supplementary Panel is currently: