Assuming it's an electric clutch version, 2 obvious things - FUSE (20 amp located behind dash), followed by the wires becoming disconnected from the clutch on the bottom of the engine.
It's possible that the clutch itself is faulty, but it's rare that they simply stop working altogether. Usually, they wear and become weak to the point of becoming unuseable, before they stop engaging altogether.
(phil_saunders(a)bigfoot.com)
Phil Saunders, June 2013
