Ryanair has accused trade union Fórsa of collapsing mediation talks aimed at resolving a number of issues between the two sides.
Last night, it was announced that directly employed Ryanair pilots based in Ireland, who are members of the Irish Air Line Pilots' Association, would strike for 48 hours from midnight on 22 August.
The move comes after 94% of IALPA members voted in favour of industrial action in this dispute over pay and conditions.
Announcing its strike plans, Fórsa said that "only a substantive counter proposal from Ryanair management, which properly addressed all areas of the IALPA claim" would convince pilots not to strike next week.
The union said "no such counter-proposal was made".
Speaking on RTÉ's Morning Ireland, Ryanair's chief people officer Eddie Wilson said the move was "absolutely extraordinary" and said the union seemed to be in a rush to go on strike.
He said Fórsa arrived at mediation talks yesterday with a prepared statement saying that mediation had failed, which was read before the meeting had got under way.
"Mediation is about engagement and we reject absolutely the charge that we did not engage with them," Mr Wilson said.
He also claimed the union demands amounted to a 100% pay increase.
Mr Wilson said Ryanair had proposed a number of potential solutions to the pay dispute, including pay scales or increases over three to four years.
The Irish Travel Agents Association (ITAA) has said it understands that holiday flights to Europe will be prioritised by the airline in an effort to limit disruption to passengers.
The ITAA said that "similar to strikes held last year, flights between Ireland and the UK are likely to face the most disruption".
The dispute with Irish pilots comes as Ryanair staff in three other European countries are set to go on strike.
Yesterday, unions representing cabin crew in Spain announced plans for ten days of strike action in September over the airline's plans to close several bases in the country.
These closures are planned following delays in the delivery of Boeing 737 Max planes.
UK-based pilots who are members of the British Airline Pilots Association have voted to strike over two days next week and for three more days from 2 September.
Meanwhile, Ryanair's Portuguese cabin crew trade union members are also due to strike for five days from Wednesday in a dispute over leave.