In Sumukan Ltd v Commonwealth Secretariat [2007] EWCA Civ 1148, the Court of Appeal has held that a failure to comply with contractual requirements relating to the appointment of an arbitrator had the effect of invalidating the appointment. Setting aside the first instance judgment of Toulson J, the Court of Appeal held that the arbitrator lacked jurisdiction and that the arbitral award should be set aside pursuant to section 67 of the Arbitration Act 1996.

The judgment of the Court of Appeal contains several points of interest, including a discussion of the circumstances in which a failure to comply with appointment procedures will invalidate the tribunal's jurisdiction, and confirmation that the "de facto" doctrine has no place in arbitration law.