The U.S. Commerce Department last week slapped preliminary anti-subsidy duties of 220 percent on Bombardier's new jets, after a complaint from Boeing, which could effectively triple the price of the aircraft and shut it out of the U.S. market if upheld.
A second preliminary levy of 80% has been loaded on the sales of aerospace manufacturer Bombardier.
"These anti-dumping duties on Bombardier's CSeries aircraft unfairly target Canada's highly innovative aerospace sector and its more than 200,000 workers - and put at risk the nearly 23,000 U.S.jobs that depend on Bombardier and its suppliers", Freeland also said.
Specifically, Boeing charges that Bombardier previous year sold Delta Air Lines 75 CS100 aircraft for less than it cost to build them.
The decision adds 79.82 per cent to 219.63 per cent in preliminary countervailing tariffs once deliveries to Delta Air Lines begin next year.
But whether or not Bombardier's jets will face import duties of 300 percent, Boeing may have lost a major sale in Canada.
The latest duty matches the amount originally proposed by Boeing, before it revised its request to 143 per cent because of Bombardier's refusal to provide certain information to the Commerce Department.
After the first duty was announced on September 26, Canada and Britain threatened to avoid buying Boeing military equipment, saying duties on the CSeries would reduce USA sales and put thousands of Bombardier jobs in their countries at risk.
Boeing added that the duties are the result of Bombardier deliberately trying to violate trade law.
Bombardier said the complaint can not be justified because Boeing did not have a plane that matched the Delta specifications when the bid was awarded to the Canadian aircraft manufacturer in 2016.
"These tribunals are like the right arm of the large corporations of Boeing", said Dave Chartrand, Quebec co-ordinator of the International Association of Machinists and Aerospace Workers.
He said workers will fight even harder to get the duty reversed.
USA trade officials on Friday ruled that Bombardier Inc. unfairly discounted sales of a new jetliner, setting up a battle as to whether Boeing Co. suffered any harm from competing with its Canadian rival. The firm order for 75 aircraft had a list price of US$5.6 billion, although large orders typically secure steep discounts.
Canada has accused Boeing of "manipulating the US trade remedy system" to eliminate competition, and vowed to keep raising concerns with the US, Foreign Minister Chrystia Freeland said in a statement.
The row has caused concerns over jobs in the United Kingdom, with Bombardier employing some 4,000 people in Northern Ireland.
Champagne warned that "there will be consequences" - essentially repeating Trudeau's threat to cancel the planned purchase of the Super Hornets.
Prime Minister Theresa May has lobbied President Donald Trump over the row, with Defence Secretary Sir Michael Fallon warning Boeing its actions could jeopardise future UK Government contracts.