The price of Canada's new fighter jets isn't fixed, a Conservative MP said Monday, admitting there's a chance it could go up.

After spending months maintaining it will cost $9 billion to buy the 65 F-35 fighter jets, plus between $250 million and $300 million a year to service the fleet, the parliamentary secretary to the minister of national defence said the price isn't firm.

"It's not a firm, fixed price," Hawn told Rosemary Barton on CBC's Power and Politics. "[But] all things factored in suggest to use that we will be paying somewhere between $70 and 75 million [a plane]."

Hawn says the figure is based on discussions with the other eight countries who have signed an agreement to buy the planes and on what the planes' parts will cost.

Hawn says U.S. Secretary of Defence Robert Gates announced last week the planes are "below the cost curve, meaning the good side of the cost curve" and progressing well.

He disputed a cost projection by Kevin Page, the parliamentary budget officer, that suggest the jets could cost $29.3 billion between the purchase price and maintenance costs for the fleet over 30 years.

Page should have spoken with Lockheed Martin, the company making the jet, but didn't, Hawn said.

'Millions of pages'

Last Friday, Hawn said the government would try to turn over more information to MPs. He said there are "probably millions of pages" about the costs associated with buying and maintaining the Joint Strike Fighters, but it's hard to release the information because Canada is working on the purchase with eight other NATO countries, who all have a say in what defence officials can give out.

Liberal finance critic Scott Brison has requested more cost information on the F-35s. Commons Speaker Peter Milliken ruled last week Parliament has the authority to demand the information, and MPs will debate the issue in committee Wednesday and Thursday.

"It's not an unfair question to say 'where's the information?', and we're going to work to get as much of that as we can," Hawn said last week. "Not all that information is ours to give. We liaise with those [NATO] folks and we will work at getting as much information as we can."

He wouldn't say when Canadians could expect to see more information.

Page said last week the "total ownership" cost estimate from the Department of National Defence over the same period amounts to $17.6 billion, based on his calculations.

Hawn said he disagrees with Page's methodology.

"Some of the assumptions he made were based on speculation based on price escalation that was based on dollars per pound. That's not the way we buy our planes, dollars per pound," he said.

The difference in figures prompted accusations from opposition parties the Conservatives are being dishonest with Canadians about the fighter jet deal, which was announced last summer.