The EFTA Court vs Liechtenstein’s Constitutional Court

On July 4 2023, the Court of the European Free Trade Association (EFTA) issued its advisory opinion in RS v Steuerverwaltung des Fürstentums Liechtenstein. Liechtenstein’s Constitutional Court had already found in 2020 that a difference in tax rate on income for resident and non-resident employees was incompatible with the free movement of workers. Nonetheless, the Administrative Court of Liechtenstein found it necessary to refer the exact same issue to the EFTA Court, upon which the EFTA Court came to a similar conclusion as the Constitutional Court. The reason thereto? The Constitutional Court had suspended the annulment of the national law for reasons of legal certainty. The question consequently arose of how the national court should further proceed. Should it immediately give full effect to the law of the European Economic Area (EEA) by following the EFTA Court and disapplying the national legislation, or should it give priority to the findings of its own Constitutional Court and nonetheless apply the national legislation, even if that legislation breaches EEA law? How should the national court deal with this conflict of allegiance?