Ryanair has announced it will cut October capacity by a further 20%.
This is in addition to the 20% cut announced last month.
It means the budget carrier will operate at around 40% of October 2019 capacity.
However, it expects to maintain load factors in excess of 70%.
Ryanair has blamed the effect of "continuous changes" to EU government travel restrictions and policies on "customers’ willingness to make forward bookings".
"In some countries, most notably Ireland where the government has maintained excessive and defective travel restrictions since 1 July, Covid-19 rates have risen in recent weeks to 50 per 100,000 population, more than double those of Germany and Italy where intra-EU air travel was freely permitted since 1 July.
"Ryanair welcomes the EU Commission’s plan to remove intra-EU travel restrictions, subject only to the ECDC [European Centre For Disease Prevention and Control] weekly update on Covid case / positive test trend rates by EU country and region, and calls for this coordinated approach to be immediately implemented by all EU states, especially Ireland, so EU citizens can make essential bookings for business and family travel, free from the worry of flight cancellations and/or defective quarantine restrictions."
A Ryanair spokesperson added: "We are disappointed to reduce our October capacity from 50% of 2019 to 40%. However, as customer confidence is damaged by government mismanagement of Covid travel policies, many Ryanair customers are unable to travel for business or urgent family reasons without being subjected to defective 14-day quarantines.
"While it is too early yet to make final decisions on our winter schedule (from November to March), if current trends and EU governments’ mismanagement of the return of air travel and normal economic activity continue, then similar capacity cuts may be required across the winter period."