Laurie Hawn, Canada's first CF-18 fighter pilot and a former Conservative MP, says he was asked to resign his position as honorary colonel after he criticized the government's decision to buy up to 18 Super Hornet fighter jets.

Hawn revealed the move in a message posted to Facebook Monday night.

"Speaking truth to power can be risky. I re-confirmed that this week by speaking out rather more forcefully than was appreciated to the commander of the RCAF and the chief of defence staff," he wrote.

Hawn has been critical of the government's decision to buy the Super Hornets as an interim measure to fill what it calls a capability gap in Canada's air force. In his Facebook post, Hawn called the gap "fabricated," arguing the decision to buy the interim jets was "100 per cent politically motivated."

Hawn favours Lockheed Martin's F-35 Stealth Fighter as a long-term replacement for the CF-18s.

A U.S. Navy Super Hornet circles Naval Air Station Oceana, in Oceans, Va. in late January. Canada has opened negotiations for the sole-source purchase of 18 of the advanced jet fighters. (Murray Brewster/CBC)

Hawn said he sent the commander of the Royal Canadian Air Force, Lt.-Gen. Michael Hood, and Chief of Defence Staff Jonathan Vance an email on Friday outlining his concerns, including his view that the interim purchase of the Super Hornets is "a waste of money and time and is something, in my view, that will ultimately kill the fighter (jet) force."

CBC News has not seen the email, but Hawn said his post on Facebook included the essence of his message in a condensed version.

CBC has reported the cost of the interim Super Hornet program could run between $5 to $7 billion, based on data being studied within National Defence. Those numbers are preliminary but are backed up by U.S. congressional budget information. The government maintains there is no price tag for the new fleet yet and is currently in negotiations with the U.S. government.

Super Hornets decision 'wrong'

In an interview, Hawn said the air force commander was already aware of his concerns, but said his email might have been "too specific and direct" for the military's liking. Hawn said that after some back and forth, Hood asked for his resignation on Saturday.

Hawn said he was disappointed but wasn't surprised he was asked to resign. As for Hood and Vance, Hawn said "their hands are kind of tied by what the government's doing. And in my view what the government is doing is entirely wrong."

In an email to CBC News, a spokesperson for the air force said Hood asked for Hawn's resignation "as political advocating is not compatible with continued service as an honorary colonel."

The spokesperson also pointed to a section in the honorary colonel's handbook, which advises that those holding the position should "remain outside any public controversy concerning the Canadian Armed Forces... and never use the appointment to promote political opinion."

Hawn was appointed honorary colonel of 401 Tactical Fighter Squadron, based out of Cold Lake, Alta., in October 2015. He was recommended for the position by former chief of defence staff Tom Lawson and his appointment was approved then defence minister Jason Kenney and the Prime Minister's Office.

'More to follow'

Honorary colonels do not hold any command or authority. They are generally former officers or distinguished Canadians and their function is to promote the unit or squadron they are attached to and assist with ceremonial events and "fostering esprit de corps" or morale.

Hawn is a retired air force lieutenant-colonel, serving for 30 years before sitting as an Edmonton MP from 2006-2015. He was parliamentary secretary to the minister of defence for three-and-a-half years and served on the defence committee. He didn't run for re-election in 2015.

Hawn said he will continue to be outspoken about the Liberal government's decision to purchase an interim fleet.

"Most Canadians may not really care about Super Hornet versus F-35, but I think they do care about the waste of billions of dollars for very little return, especially if it's purely in the name of politics.

"More to follow," he wrote on Facebook.