WA utility sale ups bushfire risk: unions

Plans to sell state-owned utility Western Power have put the Barnett government on a collision course with unions, which plan an advertising blitz about the increased bushfire risk posed by privatisation.

The Electrical Trades Union and Australian Services Union say they'll fight the proposed sale, which Treasurer Mike Nahan estimates could inject a much-needed $15 billion into the state government's debt-laden coffers.

Their radio, digital and billboard advertising campaign will draw upon the recommendations of the Royal Commission into Victoria's Black Saturday bushfires in 2009, which killed 173 people.

The Commission found faulty, privately-managed power lines were responsible for causing some of the most devastating blazes.

WA Treasurer Mike Nahan told 6PR the unions were fear-mongering and helping "their Labor mates out in the polls".

"It is despicable action to go out and frighten people inappropriately and unnecessarily," Dr Nahan said.

Australian Securities Exchange-listed electricity network business AusNet Services, then named SP AusNet, was a defendant in litigation arising from Black Saturday and in February last year agreed to an out-of-court settlement with families affected by the deadly fires.