MONTREAL — The largest unions in Canada and Britain anticipate Bombardier and Boeing are in for a protracted trade battle as they prepare for the U.S. Commerce Department to confirm massive duties on imports of the CSeries aircraft.

Following a meeting with Bombardier (BBDb.TO) management Wednesday, Unifor and Unite the Union said the chances are slim that the U.S. will lower or cancel the 300-per-cent import duties applied in a preliminary ruling.

Washington is expected to vote Monday on the preliminary and anti-dumping countervailing duties announced in the fall.

"There's no question this is going to end up in front of the WTO [World Trade Organization]," Unifor National President Jerry Dias told reporters.

"You can't depend on the kangaroo courts in the U.S. to rule in favour of [Bombardier]."

A battle before the international trade tribunal would likely take months or years to resolve. Canada can also challenge the ruling under NAFTA.

Unifor and Unite also expressed serious doubts that the U.S. International Trade Commission will conclude in February that Boeing wasn't harmed by the C Series.

Boeing (BA.N) alleges the Quebec aircraft manufacturer sold CSeries aircraft to Delta Airlines at an unfairly low price thanks to financial support from the federal, provincial and British governments.

Dias, Unifor's Quebec director Renaud Gagne and Steve Turner, assistant secretary general of Unite, representing workers in Northern Ireland, met for about an hour with Bombardier CEO Alain Bellemare.

The unions from both sides of the Atlantic are meeting to come up with a common strategy to protect jobs as the U.S. is to decide whether the punitive duties will come into effect.

Dias and Turner are also expected to be in Washington in the next few days to meet with U.S. government and elected officials about Bombardier.

Unifor represents nearly 10,000 aerospace workers in Canada, including several thousand from C Series subcontractors.

"We have no confidence that the current U.S. administration will look at this in a rational way," Turner said when asked about his expectations for the decision Monday.

"We are not dealing with a rational president and we're not dealing with an administration that is really looking at the long-term interests of the United States."

Unite, which has 1.42 million members in the United Kingdom, represents about 3,000 of the roughly 4,200 Bombardier workers in Northern Ireland where the C Series wings are made.

The union representatives noted that more than half of CSeries components are made in the United States, generating some 22,000 jobs south of the border.

The union leaders said they were reassured in the meeting that the arrival of Airbus as the majority shareholder of the CSeries program would stabilize the short- and medium-term future of Bombardier's largest aircraft.

Although Unifor isn't pleased with a proposed second CSeries assembly line at Airbus' facility in Alabama, Dias said it was the price to pay for the CSeries to take off.

Airbus and Bombardier believe that this initiative will allow planes to be delivered to American customers without punitive duties.

"Of course, our concerns were going to be the impact that the Alabama assembly line was going to have on Quebec," Dias added.

"But based on the amount of opportunities, the fact that the largest market [for the plane] is outside of the U.S. if you take a look at the Asian market, Bombardier is quite confident that it's not going to have a negative impact on the Quebec