Bird & Bird‘s Brussels office has secured a landmark victory in Belgium for more than 60 airlines challenging an unfair tax.

Catherine Erkelens, the firm’s co-head of international aviation and aerospace, acted for the Board of Airline Representatives in the decade-long litigation.

Proceedings were launched in 1995 after the municipality of Zaventem, where the Brussels National Airport is located, implemented a tax charging all airlines flying through Brussels 30 cents (20 pence) for each departing passenger. The tax would have amounted to E2m (£1.4m) every year.

The airlines said that the tax was in breach of Article 15 of the Chicago Convention on civil aviation, which deals with airport charges. They argued that the tax was unenforceable because it was not linked to any particular service.

At the end of May the Administrative High Court annulled the regulation, following decisions by a series of lower courts. It is believed to be the first time the Chicago Convention has been applied outside the US.

The municipality of Zaventem was represented by Belgian firm Delahaye.