Aer Lingus employees are to be told next week of additional cuts to pay and working hours as well as redundancies.
The airline's chief executive, Sean Doyle, told staff in a video message yesterday that the Covid-19 pandemic has had a "crippling" effect on the carrier, which is part of the IAG group that also owns British Airways and Iberia.
He said that yesterday, Aer Lingus carried just 939 passengers. On Friday of this week last year, it carried 18,361.
"As you are all too well aware, we are now in the deepest downturn that the aviation industry has ever experienced," he said.
Aer Lingus informed staff and unions earlier this month that significant job cuts will be necessary as a result of the crisis. It is believed that as many as 900 of its 4,500-strong workforce could be cut.
Steep pay cuts have already been implemented. In March, Aer Lingus said that overall pay for staff was being slashed by 50pc.
"Throughout the crisis, we have engaged with all the senior members of the relevant representative bodies," said Mr Doyle in his message yesterday. "This engagement has been constructive and respectful. However, unfortunately it has not as yet resulted in an agreed way forward."
"There is now an urgent requirement to make further cost reductions given the decimation in demand for travel in the immediate term, and the uncertainty regarding future travel demand thereafter," he added.
"The unfortunate reality is that notwithstanding the workforce in its entirety taking a 50pc pay reduction, and the support provided by the temporary wage subsidy scheme, additional cost savings are now urgently needed," said the chief executive.
He added that the current 50pc pay reductions and working time arrangements will continue until the June 21, but will not be extended for all Aer Lingus workers beyond that date.
"It is no longer sustainable, and a further reduction in working hours and pay - up to and including layoffs in some areas of the business -is required and will now have to be implemented," said Mr Doyle.
"We will also now begin to implement the structural change that is required within the organisation," he added. "I appreciate that this will be very difficult for colleagues across the business, but I assure you that it is a critical requirement."
Meanwhile, Dublin-based CityJet is seeking 700 layoffs while airport operator DAA has warned of major job cuts.