The operator of Dublin and Cork airports has told staff that they are to be put on a four day week from April 26.
As a result, the daa says their pay is to be reduced to 80% of their normal salary.
It had previously committed to paying staff in full up to April 25 and asked them to take seven days leave during the period.
"It costs approximately €10 million per week to run our business and at the minute, we have almost no revenue coming in," wrote Dalton Philips, daa chief executive, in a letter to staff seen by RTE News.
"We therefore have to take further steps to reduce our costs."
The measures will continue until June 20, he said and then be reviewed.
"We can't give certainty beyond June 20 at this stage, as it will depend on the situation at that time," he said.
The pay cuts won't apply to a very small number of "highly skilled designated essential frontline staff located at Dublin Airport", who are continuing to work full-time to keep Dublin Airport open 24/7.
Mr Philips said he knows the pay reductions will involve a huge level of pain for everybody and it is not a decision that the daa has taken lightly.
It has also applied for the Government's Covid-19 Temporary Wage Subsidy Scheme, but because of its complications it will only cover around 25% of the pay bill over the next 10 weeks.