Switzerland's trade unions have warned that the expansion of the European Union could lead to lower wages.
They called on the government to ensure that working conditions would not deteriorate if an accord between Switzerland and Brussels on the free movement of people was applied to the new EU members.
The Trade Union Federation warned that dumping could ensue when the ten new eastern European countries are admitted to the 15-nation bloc.
Serge Gaillard, a senior Federation official, said the GDP of eastern European countries averaged between 30 and 70 per cent of that of the EU's existing member countries.
The body further said it would force a nationwide vote on the issue if certain protective measures were not maintained.
But the Swiss Business Federation and the main employer's organisation both dismissed claims that such a move would lead to a cut in salaries.
They said the unions were jeopardising existing bilateral labour accords between Brussels and Switzerland, which is not a member of the EU.
Gregor Kündig of the Swiss Business Federation told swissinfo last month that he was very much in favour of extending the accord on the free movement of people to the new EU members as soon as possible as he sees it as one of the cornerstones of the internal market.
"It's a chance for [Swiss] companies to find new qualified staff and they will also be able to send Swiss staff to these countries," he said.
"That is especially important for multinationals who have to be able to move personnel around easily."
The free movement accord is one of seven bilateral agreements Switzerland signed with the existing members of the EU covering trade, transport and research.
The other six will be extended automatically to the new members when they join.
However, the accord governing the free movement of people, which will lead to the gradual reciprocal opening up of the labour markets, will have to be negotiated with each of the ten new members individually.
swissinfo with agencies
There are seven bilateral agreements between Switzerland and the existing EU countries.
Six of the agreements will be extended automatically to the new members when they join.
The free movement of people accord has to be negotiated with each of the ten new members individually.