A "botched" job of selling off Canada's airports would be costly for travellers and could even threaten national security, interim Conservative Leader Rona Ambrose says.

The government is studying the potential privatization of some of Canadian airports, but has not yet made any decision.

On the eve of Wednesday's federal budget, the Conservatives tabled an opposition day motion on Budget 2017 that includes calling on the government to steer clear of any plan to sell airports that would result in higher fees or put airports in the hands of "investors or enterprises that are under the political influence of foreign governments."

Ambrose said the government has been tight-lipped around the plan, and questioned if Prime Minister Justin Trudeau could sell the "strategic assets" to corporations or to companies owned and controlled by the Chinese government.

"Who is he courting to buy these strategic assets? And if they are airports and ports, is there a national security issue at play? We don't have answers to these questions," she said.

Ambrose said Trudeau is "very enamoured" with the Chinese government and has already looked at changing the terms and conditions of sales to state-owned enterprises.

The Conservative motion calls for no airport sale plan that uses the revenues to finance the Canada Infrastructure Bank or leads to higher user fees for taxpayers or travellers.

Asked about the proposed airport sales today, Infrastructure Minister Amarjeet Sohi said there will be further discussion after the studies are concluded.

The federal government has retained ownership of major airports across the country, but has transferred the financial, management and upkeep responsibilities to local airport authorities under long-term leasing arrangements.

Address 'protectionist' threat from U.S.

The Conservative motion also calls on the government to take steps to cushion the growing protectionist and competitive threat from the United States, including no further tax hikes, new measures to address youth unemployment and a plan to balance the budget by 2019.

Ambrose said an airport sell-off could benefit shareholders at the expense of taxpayers.

"Airports, like ports, are strategic assets and it's very important that if the government is considering selling these, that there be complete transparency around the sale, who is buying it and for what reason," she said.

Interim Conservative Leader Rona Ambrose says privatizing Canadian airports could be costly for travellers and taxpayers. (CBC)

"The for-what reason is very important, because if it is in fact BlackRock investment firm or one of these large investment firms the prime minister has been meeting with, what are the terms and conditions? What is the profit margin they are looking for to justify this purchase to their shareholders?"

A partnership of major international airports, Ottawa, Vancouver and Calgary, have created a website warning that customer service would decline and fees would increase under privatization. But others are remaining neutral until there is more information.

Daniel-Robert Gooch, President of the Canadian Airports Council, said he isn't taking a position until there are more "solid details."

"We agree with [Transport] Minister [Marc] Garneau that the work shouldn't be rushed and that it take into consideration the interests of air travellers and the communities our airports serve," he said in an email.

Government 'cash cow'

The Air Transport Association of Canada is opposed to any privatization, saying it would use the aviation sector as a government "cash cow." President John McKenna said the already steep landing, rental, ramp, gate and desk fees would increase significantly.

He pointed to a report released by the C.D. Howe Institute last month called A Better Flight Path: How Ottawa can Cash In on Airports and Benefit Travellers, which estimated that selling equity in airports could net the government between $7.2 and $16.6 billion for infrastructure.

"They're just selling off assets with complete disregard for the long-term consequences of doing so," McKenna told CBC News.