The Swiss will soon go to the polls to decide whether or not to make it easier for citizens of the new members of the European Union to find work in their country.

Swiss paper Le Matin said that Swiss business was rallying behind modest plans to open the country’s jobs market to workers, but opinion polls show that, four weeks before the vote, popular support is waning.

Voters will go the polls on 25 September. The vote is seen as a litmus test for Switzerland’s relations with the EU and a “no’ vote could jeopardise a whole package of deals with Brussels and hamper the ability of Swiss firms to trade in EU countries.

“The EU could not tolerate its new members being discriminated against,” said economist Bernd Schip,s from the Swiss KOF think-tank, at a conference in St Gallen.

With economic growth forecast at less than one per cent this year, Swiss politicians and companies argue that embracing migrants from the 10 new EU member states would kick-start the economy.

However, the campaign to reject the law is gaining force among voters worried about their jobs.

An opinion poll published in Le Matin showed that the “yes” camp had fallen to 42 per cent last week, from 49 per cent in a previous poll, with 39 per cent indicating a “no” vote, compared to 36 per cent in the previous poll.

Swiss companies and industry groups have called on voters to give the green light to the law, which will allow workers from Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia, Slovenia, Malta and Cyprus to seek jobs in Switzerland.

In its defence, the Swiss Cabinet points out that a quota on the number of workers allowed in each year would remain in force until at least 2011, and that laws preventing so-called wage dumping would be beefed up.

If the opponents of the law win through, Brussels could enact a so-called guillotine clause, pulling the plug on a raft of agreements made in 1999.

“We have to win this vote,” said head of European tax and

legal advice at Price-WaterhouseCoopers Urs Landolf, speaking at the St Gallen conference. “The lion’s share of our value creation results from exchange with Europe.”