The Ambulance Service Union or ASU is a comparatively new union formed on 17th December 1999 and finally certified as an independent trade union on 17 January 2001. The ASU represents ambulance staff employed by ambulance service trusts that although part of the National Health Service operate separately from the trusts that actually run the hospitals.
Claims to be the only union in the United Kingdom formed solely and exclusively to represent the interests of United Kingdom National Health Service Ambulance Staff, a claim that would probably be challenged by the Association of Professional Ambulance Personnel.