The Bombardier trade dispute, which is threatening thousands of jobs in Belfast, will be raised in parliament later by the Democratic Unionist Party.
Its East Belfast MP, Gavin Robinson, is calling on government ministers to “up their game” after Bombardier’s C-Series jet was dealt a second US tax blow.
It follows a competition law complaint by Bombardier’s US rival, Boeing.
Boeing has alleged that Bombardier is trying to sell its C-Series jets below cost price in the US, after taking state subsidies from the UK and Canadian governments.
The US Department of Commerce is investigating Boeing’s complaint, and so far it has ruled against Bombardier twice, imposing punitive import taxes.
The tax could jeopardise Bombardier’s biggest C-Series order – 125 jets for the US airline, Delta – which was agreed last year.
A final ruling on the matter is not due until February.
Bombardier is a Canadian-based firm but it is one of the biggest private sector employers in Northern Ireland.
Components for the C-Series jet are manufactured at a purpose-built factory in east Belfast, and the project directly supports about 1,000 jobs and thousands more indirectly.
The area’s MP, Mr Robinson, described the latest US ruling as “outrageous”.
He said that added together, the proposals amounted to a 300% import tax on the C-Series which would have the effect of “quadrupling the cost of the aircraft”.
“What I have found most unsettling is the bullish statements that have come both from Boeing and from Wilbur Ross, the [US] commerce secretary.
“I didn’t expect it. I didn’t think that they would be so protectionist,” Mr Robinson told BBC News NI.
“For that reason, I’m going to be raising this in parliament because I think what we’ve been doing thus far just hasn’t been enough.”
After the initial ruling last month, UK Defence Secretary Michael Fallon warned Boeing that the dispute “could jeopardise” its defence contracts with the British government.
Canadian Prime Minister Justin Trudeau said his government would not buy Boeing’s fighter jets or “do business with a company that’s busy trying to sue us”.
But US Secretary of Commerce Wilbur Ross said the “subsidisation of goods by foreign governments is something that the Trump Administration takes very seriously”.
The Canadian government agreed to give Bombardier a CA$1.34bn ($1bn; £800m) bailout in 2015, after it teetered on the edge of bankruptcy.
The firm has also received millions of pounds in grant aid from the UK government.
Boeing argued that state subsidies have given its Canadian rival a competitive advantage, allowing it to sell it jets to Delta for less than they cost to build.
So far, the US Department of Commerce has agreed.
Stephen Kelly, the chef executive of Manufacturing Northern Ireland, said he did not believe legal action would be needed, as past trade disputes had been resolved by political compromises between governments.
“That’s where we need to get to between now and the critical period of February,” he told the BBC’s Good Morning Ulster programme.
“But in order to do that, Theresa May and the UK government really need to signal to the US authorities that they’re serious about this – that’s certainly been the case from the Canadian government and we would hope to have some of the same from our own government.”
Speaking after the second ruling, Mr Robinson said: “This is incredibly protectionist from the US to a trading partner and neighbour in Canada.
“The only comparator is one with China and if the US are going to start treating their trading partners the same way they do China, I think not only Northern Ireland and the UK – the world has a problem.”
The DUP MP said: “The is now a four-five month window where we can get a resolution, that’s where our efforts have to be.”
He added that the British government has “a lot of cards to play in their deck, but so do the Canadian government and Bombardier”.
“We’re going to have to come at it from all sides because the potential risk to Belfast and to Bombardier… is far too great.”