But he fears that rebel Labor MPs who have said they will cross the floor will lose their nerve, ultimately defeating the Liberal Party.

Mr O'Farrell is believed to have sounded out some Labor MPs to see if they are genuine in defying Premier Morris Iemma.

Mr O'Farrell refused yesterday to reveal his stance on privatisation.

Hunter Labor MPs who have said they will cross the floor are Swansea's Robert Coombs, Cessnock's Kerry Hickey, Wallsend's Sonia Hornery and Charlestown's Matthew Morris.

At least 10 Labor MPs are expected to defy the Premier and seven MPs are expected to abstain from voting.

Mr Iemma said last week he would contact Labor backbenchers who were threatening to oppose the vote.

"I've started again the process of persuasion," he said, but Ms Hornery, Mr Hickey and Mr Coombs said they had not been contacted.

It is expected to come down to the Liberals.

The Government has attacked Mr O'Farrell for saying repeatedly he will not be drawn on which way he will vote, despite an auditor-general's report last week finding no major problems with the sell-off.

Nationals leader Andrew Stoner told his local paper his party would vote "no" on privatisation.

"We face no option but to oppose any sell-off," Mr Stoner he told the Coffs Coast Advocate.

Mr Iemma made a last-ditch promise yesterday that power prices would not rise as a direct result of privatisation as they had in Victoria and South Australia.

But he warned they could increase due to other factors beyond his control.

Retailers EnergyAustralia and Country Energy would be sold and generators Delta Electricity and Macquarie Generation leased out in long-term agreements under the controversial plan.

A public share offering of a combined entity consisting of Integral Energy and generator Eraring Energy is expected to raise $10 billion, and the Government says it will save $15 billion on the cost of a new generator needed by 2014. with AAP