Advocate General Mengozzi has stated in a non-binding Opinion to the European Court of Justice (ECJ) that collective action by trade unions is in line with European law. The case concerned a strike by a Swedish trade union against a Latvian company that refused to sign a collective agreement. Although the Advocate General found that the right to collective action could restrict free movement of services within the EU, he considered that it would not be prohibited where it was carried out in line with legitimate public interest objectives such as the prevention of social dumping and the protection of workers’ rights. However, he tempered this statement with the condition that the action is proportionate, in that it should not go further than necessary to protect conditions of employment and result in a real advantage being conferred upon the workers concerned. Although non-binding, the Opinion will be influential upon the ECJ’s deliberation of the case (Case C-341/05 Laval).