The drop is largely due to Covid-19
The Parliamentary Budget Office says it believes C-I-E, which runs the three operators, will need more state support over the next year to continue to carry out services.
Revenues at C-I-E for the second half of 2020 is expected to be down compared with last year.
The Government say the strength of airline companies should survive the crisis, however it's predicting possible job cuts to remain financially viable.
