Flights to and from France and Italy have been severely disrupted by two separate strikes.
An Aer Rianta spokesperson said up to 75 per cent of the flights to and from the two countries were cancelled and advised passengers to contact their airline before their scheduled flights.
French airports were also very quiet today as public sector employees held strikes over the government's planned pension reforms.
The latest in a series of protests over plans to make people work longer for state pensions, the action halved train and bus services in Paris.
The strikes, an echo of the 1995 protests that helped oust the last conservative government, come at an embarrassing time for President Jacques Chirac as he hosts the final day of the Group of Eight summit in the southeastern spa town of Evian.
French unions are up in arms over plans to make public sector workers pay into the state pension system for 40 years, in line with the private sector, up from 37.5 years at present.
Meanwhile, Alitalia cancelled 225 flights today as hundreds of stewards and stewardesses called in sick for a fourth day running in protest at the Italian airline's plan to reduce cabin crew numbers.
Other airline employees also went ahead with a previously-planned four-hour strike against a management cost-cutting programme, leaving thousands of travellers stranded at airports around Italy.
Italy's government, which owns 62 percent of the airline, has called management and unions to talks tomorrow.
Additional reporting by Reuters
