Swiss voters are set to reject the right-wing’s bid to cap population at 10 million after an unprecedented vote.

Voters in Switzerland took to the ballot boxes this weekend, and preliminary results on Sunday morning show that nearly 54 per cent of voters rejected the proposal, with turnout exceeding 57 per cent nationwide.

Results were still pending from many of Switzerland’s 26 cantons.

The policy was proposed by the far-right Swiss People’s Party (SVP), which has fostered anti-migration sentiment over the years, notably about an influx of workers from the neighbouring European Union.

The federal government and Parliament oppose the idea. Recent polling from the gfs.bern agency suggested that it could be a close contest.

Critics warned the bid would wound Switzerland, harming sectors such as healthcare, finance, pharmaceuticals, and technology. Experts also warned the proposal would weaken critical ties with Brussels. The EU is Switzerland’s top trading partner.

Switzerland’s political system allows for “popular initiatives” to be put to a referendum if they get 100,000 backers within 18 months and are typically held four times a year.

A “yes” vote would require the Swiss government to take action to cap the population by 2050.

If the population reaches 9.5 million before then, the government would be forced to restrict asylum, family reunification and residency permits, and may have to scrap Switzerland’s EU deal on the free movement of people.

Since Switzerland and the EU eased restrictions on citizens living and working across their borders in 2002, the Swiss population has grown by 23 per cent, to 9.1 million as of the end of last year. Economic output has also increased, up 24 per cent over the same period, government data show.

No country has implemented a cap on its population, although some countries have attempted to implement strong migration curbs. The leave campaign ahead of the UK Brexit vote in 2016 strongly focused on anti-immigration sentiment.

Swiss voters have repeatedly tackled the immigration issue over the last half-century. Only one such referendum — “Against mass immigration” in 2014 — narrowly passed, after campaigners stoked fears about overpopulation and rising numbers of Muslims in the country.