Three former cabin crew of Irish no-frills airline Ryanair have won the right to protection under Belgian labor laws, despite signing Irish contracts, a union official said on Tuesday.

Differing labor laws are a topic of fierce dispute in the European Union. France and other countries oppose plans that would liberalize services by allowing service providers to work across the bloc based on home country regulations, saying that could lead to "social dumping".

In what could prove to be an important test case, Charleroi's work tribunal ruled the three should have been treated under Belgian employment law, even though they signed contracts in English based on Irish law.

"It (the court) ruled that it was competent in this matter but it considered the working place, i.e. the place where the employees start working, was the airport of Charleroi," Christine De Greef, a legal specialist at Belgium's Christian CSC Union told RTBF radio.

She also said the criterion for determining which law to apply in the case was based on the regular place of work, which was Charleroi where flights originated.

The cabin crew were fired in 2002 after a year's trial period -- double the Belgian legal limit, Belgian media said earlier.

Ryanair said it had not been informed of any decision, but would appeal if the tribunal had found in favor of the staff.

"These three former employees were let go at the end of their probation period in accordance with their contract of employment," said Eddie Wilson, Ryanair's director of personnel.