Ryanair says its attempts to telephone the Tánaiste have proven fruitless, because her office staff is "on strike".
Although her department did reply to a letter from Michael O'Leary today, Mary Coughlan has not said whether or not she is prepared to meet him, as he requests, tomorrow.
The airline has accused the Tánaiste of "ignoring" its offer to created 300 new jobs at Dublin airport.
In response, Minister Coughlan said the Government was "most anxious" to secure further investment from Ryanair.
In this evening's letter, Mr O'Leary said: "We tried to contact your department today to see if our offer of a meeting tomorrow would be acceptable, but there is nobody in the office as the receptionist confirmed that they were "on strike". Perhaps you could have somebody confirm with my office whether or not you would like to meet tomorrow."