There are more opponents than supporters of extending an accord on the free movement of people to include the new European Union member states, according to a poll.
If voters turn down the extension in September, bilateral treaties signed by Switzerland and the EU - including the Schengen/Dublin accords on security and asylum - could be threatened.
The survey, carried out on behalf of the Matin Dimanche newspaper a few days after the Swiss voted in favour of the Schengen/Dublin accords, shows that just over a third of those polled would cast a "yes" vote.
But 44 per cent of those who agreed to take part in the survey said they were against extending the labour agreement, while 21 per cent were undecided.
The number of people in French-speaking Switzerland who came out for and against extending the accord was roughly equal.
In the German-speaking part of the country, 46 per cent came out against the extension, 34 per cent said they were in favour and 19 per cent were undecided.
More than a third of those polled are worried salaries will drop, but 33 per cent said they were not concerned by this.
Swiss Foreign Minister Micheline Calmy-Rey told the Matin Dimanche that the survey was proof that the population needed to be convinced of the benefits of extending the accord. She added that a raft of planned measures would protect Swiss workers.
"For example, we can set minimum salaries," she said. "A Polish plumber who comes here will have to be paid a Swiss salary, not a Polish one."
Calmy-Rey also questioned EU claims that Switzerland’s ties with Brussels could suffer if extension of the accord is rejected in September.
Last week the EU's foreign-affairs commissioner, Benita Ferrero-Waldner, warned that a "no" in September would spell the end of Switzerland’s bid to join the EU’s passport-free Schengen area and could potentially scupper an existing set of bilateral treaties.
For Calmy-Rey, Ferrero-Waldner's remarks were unwelcome.
"It’s telling Swiss voters that if they don’t make the right decision, there will be a payback," she said. "It is unacceptable to put that kind of pressure on Swiss citizens."
The Matin Dimanche poll also asked voters whether Switzerland should join the EU.
Less than 30 per cent of those surveyed thought membership was a good thing, while 57 per cent came out against the idea.
Scepticism about joining the EU was more apparent in German-speaking Switzerland, where more than three out of five people surveyed said they were against membership.
The picture is different in French-speaking areas, where 39 per cent said they were in favour of joining the EU.
Another poll in the magazine Facts last week found that half of those surveyed were against Switzerland joining the EU.
swissinfo with agencies
Last Sunday Swiss voters accepted the Schengen/Dublin bilateral accords with the European Union on security and asylum.
On September 25 the Swiss will decide whether to extend an existing free-movement accord to include the EU’s ten new member states.
Many Swiss fear that granting free access to workers from these countries will destabilise the labour market and lead to salary dumping and unemployment.
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