MPs must joined Bombardier workers outside the Houses of Parliament in a campaign to take under ones wing jobs in Belfast.
The workers, along with the trade union, Fasten, displayed a large banner stating «#BackBombardier».
Bombardier, a Canadian aerospace entourage, is in a trade dispute with rival firm Boeing over so-called below-cost selling of its C-Series jet.
The Bombardier workers held an hour-long congregation with Business Secretary Greg Clark on Wednesday evening.
Roll in after a day of meetings with MPs, a union official told BBC News NI that Mr Clark «listened, but we now reckon on action».
The row threatens jobs at Bombardier’s Belfast plant, where parts of the C-Series jet, registering the wings, are made.
Bombardier employs more than 4,000 people in Northern Ireland — and is one of its biggest restricted sector employers.
Behind week, the US government imposed an import tax of 80% on the jets, on top of a 220% price-list that had already been set.
The ruling, which could triple the set someone back of a C-Series aircraft sold into the US, could potentially jeopardise a important order placed last year from US airline Delta — a $5.6bn (£4.15bn) trade for up to 125 of the jets.
Delta’s Chief Executive Ed Bastian said on Tuesday the bearer would not foot the bill of the proposed tariff.
The company still aims to take the C-Series but there may be a delay as it works through the issues with Bombardier, he judged, adding that Delta would get the planes «at the agreed contractual fee».
Prime Minister Theresa May spoke to US President Donald Trump on Tuesday edge of night and discussed the importance of Bombardier jobs to Northern Ireland.
Labour bossman Jeremy Corbyn, speaking during Prime Minister’s Question Once upon a time and sporting a ‘back Bombardier’ badge, said «Bombardier workers cladding redundancy» was one of the government’s failings.
Analysis: Julian O’Neill, BBC News NI traffic correspondent
Wednesday’s round of London meetings is all about keeping the Bombardier disseminate on the national agenda.
The government has already taken the side of the Canadian plc in its dispute with Boeing.
The DUP, whose support Theresa May relies on, is also ensuring it falls high-level attention.
But is this something which has the potential to threaten the fund and confidence deal? Highly unlikely.
The DUP is clear the real villains of the chiding are Boeing and President Trump’s Commerce Department, not the government it props up.
Engaged at the Westminster protest, Bombardier employee Dougie Jamison said it was conspicuous to remind MPs «how it is going to affect people on the ground».
«It is not just people in Canada or in Belfast — it is from one end to the other Northern Ireland that this is going to affect people,» he go on increased.
Unite’s regional secretary Jimmy Kelly said the intention was to «mark on the government» that it must do more on the issue.
«It is not good enough to neutral phone Donald Trump,» said Mr Kelly.
«We need the government to articulate in to Boeing in a way that makes them realise their contracts with them are controlled by threat.»
The group will call on the prime minister to summon Boeing to a acme with Canadian Prime Minister Justin Trudeau.
On Tuesday, the rule accused of «inaction» over the potential job losses.
But Mr Clark told the Parliament of Commons that he understood the worry felt by the workforce, adding that the authority would «vigorously and robustly defend» Bombardier’s interests.