THE State Government's power privatisation plans were on the verge of defeat, a meeting of about 400 union delegates addressed by seven anti-sale MPs heard in Gosford yesterday.

Jubilant power industry delegates gave standing ovations to the MPs Liberal Chris Hartcher, National Party stalwart George Souris, Green MLC John Kaye, Labor veteran Paul Gibson, Cessnock MP Kerry Hickey, The Entrance MP Grant McBride and Labor MLC Lynda Voltz who spoke for an hour at the meeting at the Central Coast Leagues Club.

Mr McBride said that if the 22 Liberals, 13 Nationals and six other MPs voted against the bill, Labor needed seven MPs to cross the floor to defeat the proposal by Premier Morris Iemma and Treasurer Michael Costa.

The privatisation bill has had a second reading in the lower house but is yet to be debated. The MPs expected the bill to be introduced in the next three weeks.

"That will be the endgame," Mr Kaye said.

The Labor MPs said support for the plan was falling away day by day and if Mr Iemma and Mr Costa put up the bill and it was then defeated, both were finished as parliamentarians.

Opposition Leader Barry O'Farrell later confirmed that the Coalition would reject the bill as it stood and Mr Souris and Mr Hartcher said there was no way the Government could meet the five conditions demanded by the Opposition.

Yesterday's meeting was organised by Unions NSW and the combined power industry unions after the state-owned power generators took them to the NSW Industrial Commission because of overtime bans that the companies feared would plunge the state into blackouts.

The 400 delegates voted to lift the bans but warned of an immediate statewide power strike if "any member is disciplined or has their employment harmed in any way".

The meeting also voted to down tools immediately if the power legislation was passed by the lower house.