09/21/2015 13:35 EDT | Updated 09/21/2016 01:12 EDT

Liberals 'living in a dream world' on F-35 cancellation, Stephen Harper says

Conservative Leader Stephen Harper is accusing Liberal Leader Justin Trudeau of "cratering" Canada's aerospace industry by promising to scrap the plan to buy F-35 fighter jets.

Sparring over the massive military procurement erupted over the weekend when Trudeau vowed, if elected Oct. 19, to exclude the F-35 from the bidding process because of its history of problems and cost overruns.

During a campaign event in St. Jacob's, Ont. today, Harper called it "incomprehensible" that Trudeau would move to harm an industry that is vital to Canada's economy.

"The Liberal Party is living in a dream world if they think we can pull out of the development project of the F-35 and not lose business," Harper said. "I don't know what planet they're living on.

"Whether it's his statements on the aerospace industry, his statements on the deficit, you name it. It shows his disconnect and a profound lack of understanding about the Canadian economy."

The Conservatives announced an agreement in principle in 2010 to buy 65 Lockheed Martin F-35s, a single-engine "stealth" fighter. But the purchase plan was put on hold two years later amid growing controversies around costs and other problems.

An auditor general's report accused the government of fudging cost projections without sufficient research. 

Hundreds of millions spent on F-35 development

Canada has invested hundreds of millions of dollars on the development of the F-35, money that has allowed Canadian companies to participate in contracts related to the program. That participation did not oblige Canada to actually buy any of the planes.

As of summer 2014, 33 Canadian companies had contracts worth $637 million U.S.

NDP Leader Tom Mulcair called Trudeau's move to exclude an option in the midst of a procurement process "one of the most surprising things" he has heard the Liberal leader say so far in the campaign.

He said the move showed a "total lack of experience."

"How can he decide the result in advance of the process? You can't do that. The basic rule of public administration is you define what you need, then you go to a public tender process and the lowest conforming bidder gets the contract," he said.

Mulcair said both his opponents have it wrong. While the Liberals are ruling out an option without having all the facts, Harper has practised "decision-based fact making" by pursuing the F-35 at all costs.

The NDP, in contrast, would embark on an open procurement process to get the right fighter jets in the air quickly,  he said.

"Because of years of indolence and lost advantage and potential by the Conservatives, we're in a tough bind," he said. "So we're going to try to get this right. We're going to define quickly what we need. We'll  start a process that will get us a fighter jet rapidly because our women and men in uniform need that, and Canada needs it" as part of our defence.

Trudeau said while Canada took part in the development program, it has no obligation to purchase planes that have been plagued with problems.

Problems, skyrocketing costs

"It no longer makes sense, if it ever did, to have a stealth, first-strike capacity fifth-generation fighter," he said. "There are many other fighters at much lower price points that we can use that have been proven, that we will actually be able to deliver in a timely way to replace our CF-18s and make sure our military has the planes it needs and also the ships we need to continue to be the country we expect us to be."

Kristen VanderHoek, spokeswoman for the Aerospace Industries Association of Canada, said as a matter of policy the association does not comment on specific government procurement programs.

The F-35 program was developed by Lockheed Martin, and was designed to promote a common system between allied partners including the U.S, Britain, the Netherlands, Italy, Turkey, Denmark, Norway and Australia.