The Quebec government says it will contest the massive duties imposed by the U.S. Department of Commerce on imports of Bombardier's C Series commercial jets, which were set, slightly lower than expected earlier on Wednesday.

In its final determination, the department said it will impose duties of 292.21 per cent, down from 299.45 per cent set in the preliminary phase, on the aircraft.

The change was caused by a reduction in the countervailing duty to 212.39 per cent, while the anti-dumping duty remains at 79.82 per cent.

"In collaboration with the federal government, our government intends to challenge the DOC's decision… to ensure protection of Quebec's interests and show that Boeing's claims are unjustified," Dominique Anglade, Quebec's minister of the economy, science and innovation, said in a statement released Wednesday evening.

"We will spare no effort in defending workers in Quebec's aerospace industry. In doing so, Boeing wants to block competition, which threatens to eventually cause serious harm to our aerospace industry as well as to the United States," the statement added.

Bombardier said it was "deeply disappointed" with the Commerce Department's decision.

Bombardier Statement on Department of Commerce Determinations : <a href="https://t.co/8P4Iukvo55">https://t.co/8P4Iukvo55</a> <a href="https://twitter.com/hashtag/Bombardier?src=hash&ref_src=twsrc%5Etfw">#Bombardier</a> <a href="https://twitter.com/hashtag/CSeries?src=hash&ref_src=twsrc%5Etfw">#CSeries</a> <a href="https://twitter.com/hashtag/Boeing?src=hash&ref_src=twsrc%5Etfw">#Boeing</a> <a href="https://t.co/EGIWUfojcZ">pic.twitter.com/EGIWUfojcZ</a> —@Bombardier

Commerce Secretary Wilbur Ross said the decision was based on a "full and unbiased review of the facts in an open and transparent process."

"The United States is committed to a free, fair, and reciprocal trade and will always stand up for American workers and companies being harmed by unfair imports," he said in a news release.

Bombardier has yet to ship any of the planes to the United States.

'Beyond all reason'

Foreign Affairs Minister Chrystia Freeland said the duties were "highly punitive to aerospace workers on both sides of the border."

"The government of Canada is deeply troubled by the protectionist nature of Boeing's allegations, which seek to advance its market dominance by excluding Bombardier's C Series aircraft from the U.S. market," Freeland said in a release. "It is beyond all reason that Boeing could be threatened with injury in a market segment it exited over a decade ago."

Delta Air Lines was originally expected to receive the first of its firm order for 75 CS100 planes next spring, but now plans to wait until the aircraft destined for U.S. customers will be built from the Airbus manufacturing plant in Alabama.

Boeing launched the trade case in April, arguing that governments in Canada and Britain subsidized the plane's development which allowed Bombardier to sell it at unfairly low prices.

A final decision rests with the U.S. International Trade Commission, which is expected to decide in February whether Boeing was harmed by the C Series.

The Chicago-based aircraft manufacturing giant said the final duty determination validates its complaint.

"Today the U.S. Department of Commerce reaffirmed the magnitude to which Bombardier has been subsidized by government funds and the extent to which it dumped C Series aircraft in the United States, selling those aircraft at prices millions below production cost in an illegal effort to grab market share in the U.S. single-aisle airplane market," it said in a statement.

The company argued that it is seeking a "level playing field" in the aerospace market.

The union representing machinists said the final determination undermines the credibility of the trade regulator.

"They have presented us with the impossible and then made us swallow the unacceptable," said Yvon Paiement, president of Local 712 of the International Association of Machinists and Aerospace Workers.

The union represents 4,700 workers at Bombardier in the Montreal area.

Union official David Chartrand added that confidence in a fair and equitable decision by the USITC is "in free fall."

"Let's hope that the protectionist climate that the Trump administration that is affecting U.S. federal institutions will not influence the work of the US International Trade Commission," he said.

"The integrity of the entire aerospace industry is at stake in Quebec, the United States and Europe."