ZURICH (Reuters) - Net immigration to Switzerland rose again last year, official data showed on Thursday, ahead of a May referendum pushed by the right-wing Swiss People's Party on ending an accord with the European Union on the free movement of citizens.
Immigration contributed a net 55,000 people to Switzerland's population last year, the State Secretariat for Migration said. The foreign population stood at 2.1 million at year's end, or around a quarter of the overall 8.5 million.
Net immigration from the European Union and EFTA countries Iceland, Norway and Liechtenstein increased by nearly 32,000, mostly as Romanians and Bulgarians took advantage of the full opening of the Swiss labour market for them as of June 2019.
The biggest groups of EU citizens living in Switzerland are from Italy, Germany, France, Portugal and Kosovo.
In a binding referendum on May 17, voters will decide whether Switzerland should take back unilateral control of immigration, if necessary at the cost of abrogating the free-movement pact with the EU that took full effect in 2007.
The referendum under the Swiss system of direct democracy is being billed as Switzerland's "Brexit moment".
The referendum drive reflects unease with the influx of foreigners. But imposing limits on EU citizens would violate bilateral accords that enhance Swiss access to the EU single market, the lifeblood of the export-led Swiss economy.
Most Swiss oppose the idea of ending the free movement pact, a poll published this month found.
Campaigning to oppose the proposition in the referendum is a priority for the Swiss government, which has struggled to put relations with the surrounding EU on a new footing.
Brussels wants the Swiss to endorse a new treaty that would have Bern routinely adopt single market rules and create a more effective platform to resolve disputes.
The Swiss government has dragged its feet for months while it tries to forge domestic consensus on how to proceed, annoying Brussels and triggering a row over cross-border stock trading. The May vote has put any progress on hold.
The treaty ran aground amid opposition that spanned the normally pro-Europe centre left to the anti-EU far right. Critics say the pact infringes Swiss sovereignty to the extent that it would never get through parliament or pass a referendum.
(Reporting by Michael Shields; Editing by Hugh Lawson)