Thompson Aero Seating is seeking 500 redundancies which equates to 40% of its work force.
The company, which makes seats for aeroplanes at factories in Banbridge and Portadown, employs around 1, 300 people and said it was "with great regret" that it was taking "this essential step".
Unite the union said around 430 people had lost their job at Thompson Aero Seating in March and the majority had been agency staff.
The aviation industry is one of many that has been hit hard by the coronavirus pandemic.
Unite says the jobs could be saved with an adjustment to the British goverment's furlough scheme. Under that scheme employees need to be furloughed by June 10.
Unite Regional Secretary Jackie Pollock called for the Executive to take urgent action.
“They must immediately secure movement from the Chancellor on the inflexibility that is currently built into the government’s Coronavirus Job Retention Scheme. At present, workers must be furloughed before June 10th to receive support under the scheme; however, this is simply not possible where companies have contractual obligations for orders which are due immediately after this date.
"This is the case in Thompsons Aero Seating and means 500 workers now face the prospect of redundancy rather than support under the furlough scheme."
