Prime Minister Theresa May has asked US President Trump to help broker a deal in a bitter aerospace trade dispute which could financially devastate one of Northern Ireland's biggest employers.
Canadian aerospace giant Bombardier, which employs around 4,500 people in Belfast and accounts for 10% of the region's manufacturing exports, is facing significant costs in a spat with US aeronautics powerhouse Boeing.
The dispute centres over Boeing's allegations that Bombardier received subsidies allowing it to sell its CSeries planes at below-market prices.
The US Department of Commerce is expected to announce a decision on whether to impose duties against Bombardier on September 25.
However, the UK Government has been actively lobbying in the US for a compromise between the two companies amid growing concern about the potential implications for Bombardier's Belfast operations.
The Press Association understands that the Prime Minister raised the matter with the US president in a phone call last week.
Business Secretary Greg Clark also recently travelled to Boeing's base in Chicago to discuss the potential impact of the dispute and Northern Ireland Secretary of State James Brokenshire has been involved in negotiations.
The fact Downing Street has become involved demonstrates the level of concern over the impact an adverse ruling by the US Department of Commerce against Bombardier could have on the future of the Northern Ireland factory.
Northern Ireland currently does not have its own functioning government. The Stormont Executive collapsed in January following a dispute between the two biggest parties, Sinn Féin and the DUP.
Months of talks between the parties have failed to break the political deadlock.
The DUP's Gavin Robinson, in whose constituency the Bombardier factory is based said he and leader Arlene Foster are working with the Westminster government to resolve the issue.
Around 1,000 of Bombardier's Belfast employees are involved in the manufacture of the C-Series wings at the centre of the US-Canadian trade dispute.
Davy Thompson, a union representative from Unite was among those calling for unity among politicians to urge Boeing to withdraw their complaint.
Boeing filed a petition with the US International Trade Commission and the US Department of Commerce in April, alleging that massive subsidies from the Canadian government have allowed Bombardier to embark "on an aggressive campaign to dump its C-Series aircraft in the United States".
Bombardier has rejected Boeing's claims. Bombardier said the plaintiff is a global powerhouse that has not lost any sales as a result of Bombardier.