The US and United Kingdom are on the brink of a trade war after the US Department of Commerce proposed a 220% tariff on the imported sale of Bombardier's new C-Series jets into the US - an aircraft whose wings are made in Belfast.
Boeing claimed that the Canadian firm was receiving unfair advantage by using government subsidies to sell planes at artificially low prices.
The trade-dispute process is part of "the longstanding, transparent course for examining and addressing situations where products are "dumped" into the United States at below-cost prices for the purposes of gaining market share", Boeing said by email.
Commerce Secretary Wilbur Ross says the US values its relationships with Canada, but even the closest allies of the United States must play by the rules.
The Commerce Department notes in its press releases that it has launched 48 percent more anti-subsidy and anti-dumping investigations under the Trump administration this year compared with last year.
"We won't do business with a company that's busy trying to sue us and put our aerospace workers out of business", he said.
Speaking to reporters in Belfast yesterday, Fallon said: "This is not the behaviour we expect from Boeing and it could indeed jeopardise our future relationship with them".
In the meantime, Bombardier's sole USA contract for the CS100 is with Delta Airlines, and it wasn't expected to deliver the first of that 75-plane order until next spring.
"The prime minister can not be a bystander in all of this and needs to pull every lever to ensure Bombardier jobs are protected from the bullying behaviour of Boeing". I'd say that the long-term partnership is being undermined by this behaviour by Boeing'.
Workers at the Bombardier aircraft manufacturing plant in Belfast are urging Prime Minister Theresa May to use the UK's "special relationship" with the USA to rescue thousands of jobs.
September 27-A Bombardier official says the company is optimistic about the final outcome of a preliminary ruling on a trade complaint against Bombardier and its C Series passenger jet program.
The prime minister, whose minority government relies on support from a Northern Irish party to stay in power, said on Twitter that she was bitterly disappointed by the decision. Bombardier isn't scheduled to begin delivery of those planes until early 2018.
When pressed on Sir Michael's warning, the Prime Minister said: 'We have had a long-term partnership with Boeing.
Bombardier Inc. remains confident that it will win orders for its C Series jetliner this year, even after losing a ruling in a trade battle with Boeing Co. that essentially shuts off the US market. That left Bombardier's train-making unit, the company's largest, on its own against the new European giant and Asian heavy hitters such as China-based CRRC Corp. and Hitachi Ltd. of Japan.
"Boeing may have won a battle but let me tell you, the war is far from over and that we shall win", he said in Quebec City.
"What is going to be fascinating is that the Bombardier case will open the eyes of senior service chiefs to the fact that Britain is less important to the United States", Tusa said.
"Unfortunately, it's not a surprise", Foster told Sky News.