Representatives of Swiss business and farmers on Wednesday launched a campaign to safeguard the country's agreements with the European Union.
They are anxious to ensure that voters in Switzerland accept an extension to the free movement of people treaty to cover new EU members Bulgaria and Romania.
The issue comes to a nationwide vote on February 8, after the youth wing of the Swiss People's Party and two marginal rightwing parties gathered enough signatures to force a referendum to exclude the two countries.
Bulgaria and Romania joined the EU in 2007.
Every third job in Switzerland depends on trade with the EU, according to Gerold Bührer, the head of the Swiss Business Federation, economiesuisse. He warned that many businesses would be badly hit if there were a "no" vote.
The agreement on the free movement of people allows nationals of one country to live and work in any one of the others.
The People's Party claims that extending the agreement will increase unemployment in Switzerland, something business associations dispute.
"The bilateral agreements allow us equal market access to Europe despite the difficult economic environment," said Bührer.
The agreements with the EU stipulate that if one agreement is changed, the whole package – which includes areas such as research, security and asylum policy – are automatically scrapped and have to be renegotiated.