Aer Lingus blamed the 14-day quarantine rule for worsening the "catastrophic" Covid-19 crisis for the aviation industry as it announced 500 job losses.
Staff were told yesterday the redundancies will affect workers across the IAG-owned business.
They include roles in in-flight services, ground operations, maintenance, engineering and head office.
The airline has informed Social Protection Minister Regina Doherty that job losses are anticipated among the workforce of 4,500.
Aer Lingus said in a statement the crisis was having a catastrophic effect on the aviation industry.
It said it was currently operating less than 5pc of its normal schedule and had no certainty regarding the restoration of services or future demand for travel once services resumed.
"The situation is exacerbated in Ireland by the 14-day quarantine requirement for arriving passengers and travel advisories, which advise against all non-essential travel," it said.
"Ireland has failed to take steps that other European member states have taken - they have progressively restored transport services and connectivity in response to a European Commission invitation to do so".
It said it had to reduce the size of the airline in response to the crisis.
"Aer Lingus has informed the minister that headcount reductions of up to 500 employees across the business are anticipated," it said.
It added it was beginning consultations with unions.
Forsa said it would engage with management regarding the proposed job losses.
The union, which represents cabin crew, pilots and some management staff, said it aimed to minimise the number of job losses and income cuts.
An Aer Lingus spokesperson was unable to comment on the terms of the redundancy payments.
"Those details are to be discussed with employee representatives," he said.
Labour deputy for Fingal Duncan Smith said the job cuts were a hammer blow for workers and their families and showed a disregard of workers' rights.
Fine Gael TD Alan Farrell said the job losses were deeply saddening and urged all sides to engage in good faith.
"The industrial relations machinery of the State stands ready to assist all parties in an effort to reach a suitable agreement," he said.