The outcome of Sunday's nationwide ballot on tightening the asylum laws has turned into a cliffhanger, with voters evenly divided on the issue.
The United Nations says the controversial rightwing proposal would make Swiss asylum laws among the most draconian in the industrialised world.
But the Swiss People's Party, which tabled the proposal, has said the new laws would cut back on abuse of the country's asylum system by limiting the number of asylum applications.
Benefits would also be cut to those whose requests have been turned down.
Critics also say a "yes" vote could put in jeopardy Swiss plans to become a signatory to the European Union's Dublin treaty, governing asylum.
"Dublin makes clear which country is responsible for dealing with an asylum application," said Jürg Schertenleib of the Swiss Refugee Council. "Why should the EU conclude a parallel treaty with a country which refuses even to deal with asylum applications?"
Government rejects initiative
The Swiss government has tried to persuade voters to reject the asylum initiative, arguing that it would be difficult to enforce and would make it harder to distinguish between bogus and genuine asylum claims.
Under the terms of the proposal, asylum seekers would be prohibited from filing an application in Switzerland if they had passed through a so-called "safe" country first.
Asylum applicants who arrive in Switzerland through one of its neighbours would be forced to return to those countries to have their applications processed.
The Swiss justice minister, Ruth Metzler, has said the proposal - if it is given the green light by voters - would be expensive to enforce, counterproductive and would damage Switzerland's humanitarian tradition.
Jürg Schertenleib told swissinfo the proposals would see Switzerland shutting the door on most asylum seekers.
"Switzerland is surrounded by safe third countries," he said. "As nearly 95 per cent of people making asylum applications in Switzerland arrive by land, almost everyone would be excluded."
Proposal under attack
The proposal has also come under attack from the United Nations High Commissioner for Refugees, Ruud Lubbers, who said the proposed laws would lead to some of the toughest asylum restrictions in the industrialised world.
But the People's Party claims the restrictions would discourage so-called economic migrants, masquerading as asylum seekers, from coming to Switzerland in search of work.
Proponents of the initiative say a general work ban would significantly reduce the number of people coming to Switzerland simply to earn money.
Aliki Panayides of the People's Party said one of the objectives of the initiative is "to frighten [asylum seekers] off. The aim for many people is to get here, to stay here and to work to have money to send back home.
"If we don't let them asylum seekers work, they will go somewhere else because it won't be attractive to stay in Switzerland."
Switzerland already has a three-month work ban for asylum applicants, as well as a further three-month ban for those whose requests have been denied but which are being appealed.
There are currently over 26,000 recognised refugees in Switzerland.
Around 95 per cent of asylum seekers arrive in Switzerland by land.
Recent opinion polls show 43 per cent in favour of the initiative with 37 per cent against.