ROME (AP) — Italian officials are warning that Switzerland could face consequences after voters in the border canton of Ticino approved a referendum calling on authorities to grant preference to Swiss workers over foreigners in employment.

Fifty-eight percent of Ticino voters approved the measure, an outgrowth of the Swiss nationalist efforts to limit EU workers in Switzerland.

Foreign Minister Paolo Gentiloni tweeted that while the referendum had no practical effect, "Swiss-EU relations are at risk without free circulation of people."

Free movement is part of Swiss-EU agreements concluded in 1999.

In an ironic twist, the most vocal Italian critic of the Swiss result was Roberto Maroni, leader of Italy's anti-immigrant Northern League. He complained that the vote would harm Italians who work in Ticino and vowed to protect their rights.