Influential senators on Thursday demanded that the Bush administration provide more details about its move to place its controversial National Security Agency domestic spying programme under supervision by a special court.

Patrick Leahy and Arlen Specter, the top Democrat and Republican on the Senate judiciary committee, told Alberto Gonzales, the US attorney-general, that the Bush administration needed to provide some more information about the surprise decision this week to allow a secret intelligence court to monitor electronic domestic spying.