GENEVA  — Voters in Switzerland have narrowly backed a proposal to limit immigration to the Alpine republic.

Swiss television SRF reports that the referendum backed by the nationalist People's Party was approved by an extremely narrow margin Sunday.

Initial results show some 50.5 percent of voters, with about 49.5 percent against. Approval was strongest in German and Italian-speaking parts of the country, and in rural areas.

The Swiss government and most parties opposed the plan to introduce quotas for all types of immigrants, saying it could harm the economy and Switzerland's relationship with the European Union.

The outcome means that the government will have to renegotiate painstakingly forged treaties with the EU on the free movement of workers.