Theresa May has directly pressured Donald Trump again over the transatlantic trade row that threatens thousands of Bombardier jobs in Northern Ireland.
Downing Street said the Prime Minister spoke to the US president yesterday when she stressed "the importance of the jobs provided by the Bombardier factory to the people and economy of Northern Ireland".
The call came just hours after a senior Labour MP told the House of Commons she feared Westminster is turning its back on Bombardier workers in east Belfast.
Their jobs were considered "a fair price to pay" in order for the Government to obtain a trade deal with the US after Brexit, Shadow Business Secretary Rebecca Long-Bailey claimed.
She told MPs she believed that Northern Ireland Secretary James Brokenshire and International Trade Secretary Liam Fox had been "somewhat quiet" on the issue.
"Are they afraid of being exposed in Northern Ireland for their failure to protect jobs, or are they so keen to score a sweetheart trade deal with the US that they simply want to wash their hands of this matter?" she asked.
"Clearly, politics is being put ahead of the welfare of workers in Northern Ireland."
Ms Long-Bailey went on to say that she feared Bombardier and its workers "are considered a fair price to pay for a post-Brexit trade deal with President Trump by this government".
However, Business Secretary Greg Clark told MPs that the Government would not rest until the bitter dispute between aerospace giants Boeing and Canadian-owned Bombardier - which employs 4,000 people in Northern Ireland - is brought to a resolution.
"We will continue to vigorously and robustly defend Bombardier jobs in Belfast and work with the Canadian government to do so," he said.
Mr Clark added that complaints by US firm Boeing over a deal for the sale to Delta Air Lines of Bombardier C Series planes into the US are "bitterly disappointing".
The complaint has so far resulted in tariffs of 300% being applied to the C Series jets in the US, which could jeopardise the deal and the future viability of Bombardier's Belfast operations.
Boeing secured a finding from the US Department of Commerce two weeks ago that Bombardier had unfairly benefited from government subsidies in launching the C Series.
But Mr Clark said that all new aircraft programmes benefited from subsidies - including Boeing's own 787. He added the UK government rejected the US claim that £113m in UK funding for the manufacture of the C Series wings was unfair support.
But North Antrim DUP MP Ian Paisley said he believed the UK government would work to resolve the row.
"Come crunch time the British Government should not be found wanting in how they defend British workers in Northern Ireland," he added.
Afterwards, DUP East Belfast MP Gavin Robinson claimed the trade dispute and threat to jobs was clearly important to the Government as "there were Ministers from across the Cabinet on the front bench" during the Business Secretary's statement.
And he hit out at the US politician who last month told Bombardier that "if you're building wings for a plane that doesn't get built, that's a problem", as he announced huge punitive tariffs.
Mr Robinson said: "I have made clear my bitter disappointment at comments from Commerce Secretary Wilbur Ross, not least because the impact on Bombardier is not limited to Canada and Northern Ireland.
"A significant portion of the supply chain for the C Series is located in the US and there are thousands of American jobs supported by it."
Meanwhile, workers from Bombardier in Belfast will today press for Government action to help secure their jobs.
They will travel to London and unveil a giant banner outside Parliament urging MPs from all parties to defend their jobs.
The workers want Mrs May to summon Boeing to a summit with Canadian prime minister Justin Trudeau and workforce representatives.
Unite assistant general secretary Steve Turner said: "The British government has a duty to defend UK manufacturing jobs against the bullying behaviour of Boeing.
"A failure to do so will signal that any ambition ministers have for a coherent industrial strategy is effectively in tatters and that they are happy to put Trump's 'America First' policy ahead of UK manufacturing jobs."