The Swiss government, business groups, and left-wing politicians have urged voters to reject the population control initiative, dubbed Ecopop, saying it will imperil ties with the European Union, already damaged by a previous anti-immigration vote in February.

But the 20 Minuten poll showed 53 percent of Swiss could envision backing the tighter controls, compared to 44 percent who oppose it.

A similar poll published by the paper in the weeks after the prior immigration vote showed only 40 percent support for the Ecopop initiative.

The poll's authors said the survey was conducted online on Oct. 15 with 13,397 voters. Results were then weighted by voter demographic, geography, and other political variables in order to better represent the Swiss voting population.

Still, the method of polling is seen as less reliable that of Berne-based research and polling institute gfs.bern, which is due to publish its own poll on Ecopop on Friday.

The Ecopop vote was initiated by a group which argues that immigration has led to overcrowding in Switzerland, endangering the country's natural resources. It has tapped into concerns about rising rents and crowded public transport.