Switzerland is to hold a landmark vote on a right-wing party’s proposal to restrict the nation’s population to 10 million, amid divisions over immigration.

The proposal, put forward by the country’s largest political grouping the Swiss People’s Party (SVP), would require the government to act before the population – currently at 9.1 million – rises to the proposed 10 million upper limit.

If the vote, due to be held on June 14, is passed, the government would have to refuse entry to newcomers including asylum seekers and the families of foreign residents once the population reaches 9.5 million.

If the population hits 10 million, the government would be forced to end its free-movement agreement with the European Union (EU), which is Switzerland’s largest trading partner.