Bombardier was last night preparing itself for a new setback that could put thousands of its Northern Ireland workers at risk.
The US government appeared set to rule in favour of Boeing, accusing Bombardier of 'dumping' - selling at a cut-price or below cost - its C Series aircraft.
In a preliminary ruling last week the US Department of Commerce imposed a 220% tariff on the jets following a complaint by Boeing that its Canadian rival had received State subsidies.
The C Series wings are built in Belfast, where thousands of jobs are now at risk.
Some reports were speculating late last night that Bombardier was expecting to be hit by additional export duties on the C Series when the Department of Commerce announced preliminary anti-dumping costs.
The aerospace giant had said it wouldn't be shocked if the US announced another "absurd" duty.
Colin Bole, Bombardier's sales chief for commercial aircraft, said the company expected the second duty to be a "significant number", but one that also made no sense.
Shortly before the second report was due to be released last night, Bombardier appeared to be trying to put its own spin on things.
Reuters reported that Bombardier's aerospace business spent $2.4 billion in the US last year, and made use of more than 800 suppliers in all but three US states.
The figures were said to have been part of a confidential Bombardier paper seen by Reuters.
The report suggested more than half of the materials Bombardier buys for the C Series come from US suppliers.
As well as having the potential to hit jobs, the Bombardier-Boeing trade row could damage the wider economy and the peace process, the Republic's Foreign Minister Simon Coveney told a senior American official this week.
And President Donald Trump was made aware, during a phone call with Prime Minister Theresa May, that the ongoing dispute would affect Northern Ireland directly, according to DUP leader Arlene Foster.
Speaking to the Belfast Telegraph yesterday, Mrs Foster said the Prime Minister was completely aware of "the damage this would do to Bombardier, and the Northern Ireland economy".
"She tells me that the President seized that this was Belfast when she spoke to him," Mrs Foster said.
"He said: 'Oh, right, so that would have a big impact on Northern Ireland'.
"So he knows it's not a Canadian issue, and this is going to have an impact on Northern Ireland."
"This is only the second part of a two-pronged complaint.
"I did at the Conservative Party conference have an opportunity to meet with the High Commissioner for Canada, and obviously I spoke to the Prime Minister at the conference about Bombardier.
"It is around the twin-track approach, putting forward the evidence to show that there hasn't been any damage to Boeing, but at the other side to have the political track going as well, to have the Canadian government, the American government, to put the pressure on there.
"This is a global issue, and I fully understand that. And that is why we need the support of our own government, working with the Canadian government."
The US International Trade Commission will ultimately decide in February whether to uphold or reject the proposed tariff.