A two-and-a-half-year-long inquiry into the Berejiklian government's decision to relocate the Powerhouse Museum to Parramatta has urged the billion dollar project be immediately abandoned as it raised fresh doubts over the adequacy of the new museum's international design brief.

The Powerhouse Museum should instead be given a cash injection and restored to its former glory, a new satellite museum be considered in western Sydney and Parramatta be given its own world-class institution, the upper house committee found in a report timed to exert maximum political pressure on the government four weeks out from the state election.

The National Trust joined that call to cancel its planned move of the' Powerhouse Museum from Ultimo but the NSW Premier said there was no turning back: ''The Powerhouse in western Sydney is part of the future of western Sydney.''

Arts minister, Don Harwin, announced final jurors to select the design for the new museum, public space, and pedestrian bridge.