Canada's defence minister has signalled that the F-35 will not be excluded from the forthcoming competition to replace the air force's aging fleet of fighter jets.

One of the new Liberal government's main campaign pledges was to buy a less expensive aircraft and plow the savings from the stealth fighter program into the navy.

But Harjit Sajjan says he is focused on finding the best aircraft to replace the country's CF-18 jets before they reach the end of their useful service life.

Speaking on a conference call from Iraq, he was asked twice whether the F-35 is being excluded from the open competition the Liberals plan to run and in each case he ducked the question.

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Justin Trudeau's promise to scrap the F-35 program was seen by some as one of the turning points of the federal campaign. (Adrian Wyld/Canadian Press)

"My focus isn't about F-35, or any other aircraft," he said. "We will open it up to an open process."

Sajjan did say that the military is reviewing the basic requirements for the fighter, a document that is steeped in controversy since a scathing auditor general's report forced the Harper government to put the $44-billion program on hold.

Michael Ferguson's 2012 investigation found that the statement of requirements, an important document that sets out what the military needs in a piece of equipment, was written after the Conservative government had signalled its intention to buy the F-35.

Since the fighter fleet will be with the air force for decades, Sajjan says they have to make sure they get the research right.

"Right now we are going through the process where you build the right requirements from that," he said.

"And from those requirements there will be a certain capability and we will open it up to an open process and from that, a decision will be made for a replacement of the F-18."

Requirements could be reset

Dave Perry, an analyst with the Global Affairs Institute, said an independent public works panel, which the Harper government struck to examine the replacement program, did an exhaustive study and produced volumes of research.

One of the things it didn't do was examine — or question — the basic state of requirements, he said.

The panel looked at information from five rival aircraft makers: Lockheed Martin, the F-35's manufacturer; Boeing's Super Hornet; EADS Eurofighter, also known as the Typhoon; Dassault's French-built Rafale; and the Saab-manufactured Gripen from Sweden.

Perry said the minister's comments suggest to him that National Defence is looking at coming up with a new set of specs "and once again crafting that document — prepping it new or potentially revising the existing one."

It is possible that the requirements could be written in such a way so as to exclude the Lockheed Martin-built jet, Perry said, thereby keeping Trudeau's campaign promise which clearly stated Canada "won't purchase the F-35."

He noted how the air force was raked over the coals and accused of favouring one particular aircraft in the decade-long bid to replace the country's fixed-wing search planes.

But Perry, who was on Sajjan's conference call Monday, said he noted how the minister underlined that it would be an "open competition."

"I didn't hear anything that was a categorical exclusion of the F-35," he said.

Deliberately keeping the stealth fighter out of the bidding would be a political and legal minefield.

When the Liberals went to replace the country's aging CH-124 Sea Kings in 2004, it chose a bid from Sikorsky Aircraft, even though the CH-148 Cyclones were basically still on the drawing board.

Rival AugustaWestland alleged political interference and accused the Martin government of excluding its bid because the aircraft on offer was the basically the same one the Liberals cancelled in 1993. The company went to court, but dropped the lawsuit in 2008.