The UK Patent Court has been thrown into disarray with the promotion of leading patent judge Mr Justice Pumfrey to the Court of Appeal.
Pumfrey J will move to the court on 30 September, but no replacement has yet been appointed, with the six-week High Court patent case between Nokia and Interdigital due to start on 15 October.
The case is highly technical and at one stage involved 29 patent infringement actions. Pumfrey J scheduled two weeks' reading before the hearing and any successor will need to be briefed for several weeks.
Failing that it is possible that Pumfrey J will have to delay his move for another month to hear Nokia v Interdigital, or a deputy High Court judge could preside.
Jane Mutimear, lead partner at Bird & Bird for Nokia, said: "There's always the possibility that he'll come back to the High Court to hear it. But I can't imagine that's the first thing on his wishlist."
The promotion highlights the shortage of judges able to hear complex patent cases.
Mr Justice Rimer was also promoted to the Court of Appeal to replace Lord Justice Chadwick, who retires in November.