Analysts say Lockheed Martin's F-35 Joint Strike Fighter (JSF) doesn't meet Canada's requirements even as earlier this week a top Canadian official raised the spectre of leaving the programme.
"We have not as yet discounted the possibility of backing out of the program," Canadian associate defence minister Julian Fantino told Canada's parliament on 13 March. "The determinate decision has not yet been made about whether we're going to purchase, buy, [and] acquire the F-35," he adds.
The Canadian government, lead by prime minister Stephen Harper's Conservative Party has been a particularly vocal supporter of acquiring the stealthy fifth-generation jet. Canada has previously said that it would buy 65 F-35s for about $9 billion.
Later, the Canadian government insisted that its position on the prospective F-35 buys had not changed.
The increasing costs and delays associated with the F-35 have been a source of controversy in Canada and other F-35 partner nations.
Canadian analysts however say that the Harper government has not fully taken into account the country's requirements, particularly with regard to patrolling Canada's vast and very sparsely populated north.
"People are really re-evaluating whether the F-35 really is the best plane for Canada," says Michael Byers, a professor at University of British Columbia and expert in northern sovereignty issues. "We're the second-largest country in the world and much of our territory is very remote."
Byers questioned whether a single-engine fighter aircraft such as the F-35 is suitable to fly missions over the vast reaches of the Canadian Yukon, Northwest Territories, and Nunavut. The swath of land is so large that it covers an area greater than half the size of Australia and is bigger than all of India.
Moreover, in recent years, Canada has not been a nation that has participated in large-scale combat operations in the opening phases of a major war-which is where the F-35 is most useful with its stealthy airframe.
"Canada has never been the tip of the spear in terms of combat operations overseas," Byers says. "So the case for a stealth airplane hasn't really been made that convincingly."
Analyst Stewart Webb of the Salt Spring Forum, a new Canadian think-tank, questioned the maintainability of the F-35's stealth coatings - especially in the harsh northern climate where temperatures can sink well below -50°C (-58°F).
While Canada needs a very long-range aircraft, Byers says, it probably does not need stealth.
According to a US Navy document, the original F/A-18 Hornet models, which Canada flies, have a combat radius of around 685km (370nm) while carrying three, 1,249lt (330gal) external fuel tanks and external ordnance. The F-35A model aircraft that Canada wants to buy is projected to be around 1,092km (590nm) without external tanks but with full internal weapons bays.
Webb alleges that Canada's Department of National Defence (DND) stacked its requirements in favour of the F-35. He contends that Canada should have considered alternatives to the JSF, but didn't. The DND should have evaluated competing aircraft such as Boeing's F/A-18E/F Super Hornet and F-15E Strike Eagle, Eurofighter Typhoon, Saab Gripen and the Dassault Rafale in a fair and open competition like Japan did, Webb says. Ultimately, Japan chose to purchase the F-35 for its F-4J Kai Phantom replacement.
"The Harper government wants the F-35," he says. "And just wants to make a bold statement saying we need to buy new, and buy new now."
Webb also says the Canadian government should have considered investing in the development of a domestically designed unmanned aircraft for patrolling the north.
Loren Thompson, an analyst at the Lexington Institute in Virginia with close ties to Lockheed, says if Canada bails out of the F-35 programme it would be a huge blow to the company and the F-35 programme.
But it would also be a huge blow to the Canadian military, he says.
"The F-35 is the only stealthy production fighter in the world," Thompson says. "Any country that doesn't have it won't have a survivable fighter 20 years from now."
Even if a nation like Canada does not conduct the same offensive power projection type missions that the US does, hardware such as fighter planes stay in a nation's inventory for two generations.
"You really need to think through all the missions you might have to fly," he says.