[GENEVA] Swiss voters on Sunday will decide whether to dramatically cut immigration numbers in the name of saving the environment, in a referendum that opponents have labelled xenophobic and disastrous for the economy.
Most voters have already cast their ballots by mail, and initial results should be available shortly after polls close at noon (1100 GMT).
Surveys have shown the so-called Ecopop initiative gaining momentum in recent weeks but still indicate it is doomed to fail.
In the latest opinion poll, 56 per cent said they would nix the proposal which maintains that the current influx of foreigners is swelling the Alpine nation's population and shrinking its idyllic landscapes and green spaces.
Supporters however stress that surveys often underestimate backing for populist initiatives and insist the country could be in for a surprise.
It would not be the first time.
Last February, the approval of an initiative demanding quotas for immigration from the European Union caught many off guard and threw non-member Switzerland's relations with the bloc into turmoil.
Foreign nationals already make up nearly a quarter of Switzerland's eight million inhabitants, official statistics show.
According to Ecopop, immigration is adding 1.1-1.4 per cent annually to the Swiss population, putting the country on track to house up to 12 million people by 2050.
"It's already getting too crowded here," Anita Messere of the Ecopop committee said, arguing that the inhabitable plains of the mountainous country were being covered in concrete at a rate of more than one metre (yard) per second.
The campaign wants to cap immigration growth at 0.2 per cent, or an addition of around 16,000 people annually, which it says would allow the number of inhabitants to increase to just 8.5 million by the middle of the century.
It also wants to help rein in over-population beyond Switzerland's borders, calling for 10 per cent of the country's development aid budget to go to family planning initiatives abroad.
The government, all political parties, employers and unions have rejected the initiative, slammed by some as xenophobic and by others as a threat to Switzerland's economy which depends heavily on immigrant labour.
Christian Luescher, a parliamentarian for the Liberal Party and co-chair of the committee opposing Ecopop, described the initiative as "absolutely absurd".
"It aims to drastically, linearly and arbitrarily reduce immigration to Switzerland, with absolutely no consideration for the needs of the economy," he told AFP, warning it would "impoverish our country".
The Swiss will also vote Sunday in two other national referenda as part of their famed direct democratic system.
Polls hint voters are also likely to reject a bid to scrap special tax breaks for rich foreigners living but not working in Switzerland, who today can choose to be levied on their spending rather than income.
Switzerland counts 5,729 millionaires and billionaires with foreign passports, who together pay around one billion Swiss francs (US$1.04 billion, 830 million euros) in taxes annually.
That is a far cry from what they would have paid had they been levied at the same percentages as average Swiss taxpayers, say the left-leaning parties and unions behind the initiative.
"This system is morally indefensible," Geneva-based student Roger Gulke told AFP.
But backers of the system insist wealthy foreigners contribute substantially to Swiss tax coffers and inject huge sums directly into the local economy, warning many will leave the country if they face higher taxation.
"You'd have to be completely crazy to wave goodbye to this godsend to our economy," Luescher said.
The third issue on the table is a call to force Switzerland's central bank to increase its gold reserves and it also appears destined to fail, according to polls.
But fear of a surprise win has stirred up global gold markets, with economists warning it would wreak havoc on trading worldwide.
The initiative would oblige the Swiss National Bank to boost its gold reserves to at least 20 per cent of its holdings, nearly three times more than today's level of seven percent.
Analysts have warned the bank would be forced to buy around 10 per cent of the annual global gold production through 2019 to meet that requirement.