The Labour Court hearing involving Ryanair management and the pilots’ union IMPACT has been adjourned until next Monday.
It is understood that during the 3.5 hour hearing, both sides made detailed submissions but it was felt that the court would need more time to consider the issues.
The hearing follows a complaint by IMPACT on behalf of Ryanair pilots.
Ryanair has never recognised unions, arguing that it prefers to deal directly with staff.
However, the Industrial Relations Act of 2001 allows unions to complain to the Labour Court if an employer will not negotiate with them.
Even if the employer ignores the proceedings, the Labour Court can issue a binding recommendation which is legally enforceable in the Circuit Court.
Ryanair Chief Executive Michael O'Leary argues that the legislation introduces compulsory union recognition by the back door, and he has threatened to mount a constitutional challenge to the legislation.
The airline's legal representatives had been expected to argue that the legislation was never intended to apply to a high pay multinational like Ryanair with internal collective bargaining mechanisms.
Arriving for the hearing, IMPACT Assistant General Secretary Michael Landers said Ryanair was entirely free to challenge the legislation.
However, he added that in the interim they were proceeding on the basis that the act is constitutional and valid.