I mean, theres probably EU provisions in place to make that kind of local ruling have teeth, n'est-ce que pas?
[0] Denmark has an opt-out from this area of EU law, which is why it is the only EU member state which needs to be directly party to the treaty; it applies to the others indirectly through the EU as a whole being a party to it
However, I don’t know whether the other aspects of Liechtenstein’s legal and political system would make that viable or not.