The cost of buying and servicing the F-35 stealth fighter jets that Ottawa has been planning to purchase has skyrocketed to about $40 billion, CTV News has learned, as the Conservative government considers alternative aircraft.

A report commissioned by the government, which will be released next week, will kick off a review of the entire jet fighter procurement process and the need to replace Canada’s aging fleet of CF-18 jets.

The report examined the cost of buying, maintaining and operating 65 F-35 jets over a period of 36 years. The soaring price tag has prompted officials to consider purchasing less expensive war aircraft. Options to be examined by an independent panel include the U.S.-made Super Hornet and Swedish-made Gripen, sources say.

The Conservatives’ plan to purchase the F-35 jets has been mired in controversy since a scathing auditor general's report accused both National Defence and Public Works of hiding the true cost of the project.

Ottawa said the program would cost between $14.7 billion and $16 billion, but auditor general Michael Ferguson and Parliamentary Budget Officer Kevin Page disputed those figures.

Ferguson accused the Defence Department of low-balling the estimate by not including operating expenses, and said it would actually cost more than $25 billion, but government officials denied trying to hide anything.

Page had estimated it would cost $29.3 billion to purchase and maintain the jets.

Now, it looks like the cost would exceed both of those estimates.

Alan Williams, a former senior procurement officer with the federal government, said the price of the “complex” jet program has been going up since Ottawa initiated the procurement process.

“We ought to wait until the development is done and the platform is operational,” he told CTV’s Power Play Thursday.

“But we dipped our toes into the water much too early in the program, without knowing the cost or the capability. And that’s why we’re saddled with this situation today.”

Conservative MP Michelle Rempel said the government is committed to being transparent on the issue and following the recommendations of the auditor general’s report in April. She said the report on F-35 costs will be made public soon.

“We want to make sure that we get this right and we’re taking it really seriously,” she told Power Play.

However, NDP defence critic Jack Harris said the “sticker shock is going to make people say this is not something that’s affordable.”

With a report from CTV’s Ottawa Bureau Chief Robert Fife