OTTAWA - The parliamentary budget officer is set to table a report expected to propel the Conservative government's $16-billion stealth-fighter program into the political stratosphere.

Kevin Page was asked by the Liberal opposition to look at the cost of the deal with U.S. defence giant Lockheed Martin, and the potential impact of the F-35 Lightning II on the Canadian defence industry.

The Liberals say they would halt the planned purchase and hold an open competition to replace the air force's aging CF-18 jetfighters, which are expected to reach the end of their life by 2020.

The Harper government has termed the Liberal plan irresponsible and warned the country risks losing $1 billion by bailing out of the F-35 program.

All of the opposition parties have complained about the $9-billion purchase price and the estimated $7-billion service bill, which is stretched over 20 years.

Defence Minister Peter MacKay has insisted the price tag for 65 of the high-tech, highly automated jets is firm. He's also said he's confident that maintaining the F-35 won't run much more than the $250 million currently spent every year to service the CF-18s.

Page's report is expected to parse the government's assumptions.

Sources said Wednesday the report has been the subject of extensive peer review by agencies in the U.S. and Britain, which also has a big stake in the F-35 program.

Political sparing over the fighter has been frequent in the House of Commons.

"What they are telling us is that we're going to buy aircraft, but we're not going to tell you how much they cost," said Liberal MP Marc Garneau on Wednesday.

"They refuse to issue a tender to ensure the Canadian air force is getting the best aircraft at the best price."

MacKay said cancelling the deal would "endanger the lives of Canadian pilots" and "endanger the sovereignty of this country."

The Conservatives say they are committed to buying the aircraft, but have yet to sign a formal contract. That is expected in 2014, with the first jetfighter delivered three years later.

The deal is unique in that Lockheed Martin required countries to contribute funds up front for the development phase. The cash also bought premium access for defence industries in those participating nations to bid on F-35 contracts.

The Liberals have complained there are no guarantees of industrial benefits with the stealth fighter, unlike regular defence contracts which mandate corporations to match dollar-for-dollar the purchase cost.