More than 200 Swiss union members have demonstrated in Strasbourg against European Union plans to create a free market in the services sector.
Around 40,000 protestors from around Europe showed up in France as the EU discussed the Services Directive that aims to liberalise areas such as construction, restaurants and consulting.
The European parliament is debating the proposals, also known as the Bolkestein Directive after internal market commissioner Frits Bolkestein, for the first time on Tuesday.
The aim of the directive is to create an open market for services comparable to the free trade of goods.
Switzerland's largest union, Unia, acknowledges that the directive will not affect Switzerland directly in the short term but fears it will make it harder to protect workers from wage dumping in future.
"This directive will make it more difficult for further treaties in a way that is unacceptable for unions in Switzerland," Unia spokesman Hans Hartmann told swissinfo.
"Our strategy for managing open borders is to get the Swiss government to introduce stricter legislation to make it more acceptable for the working class.
"The Bolkestein Directive would make this process more difficult."
But Professor Robert Zäch of Zurich University believes opening Swiss borders further would be beneficial if the price of goods also dropped to EU levels.
Zäch, a member of the competitions commission, said the Swiss pay up to 40 per cent more for some goods than in many EU countries, which drives up the cost of living.
"Opening up the service sector market would put additional pressure on wages, so I can understand the arguments of the unions," he told swissinfo.
"If our workers could buy food at 20-40 per cent less, then wages could come down. The high price island issue must be tackled otherwise opening up borders will be unfair to businesses and workers."
Switzerland would not automatically have to sign up to the Bolkestein Directive if it is made EU law, according to the Swiss EU Integration Office.
Switzerland broke off negotiations with the EU over opening the service sector market in 2003. Current treaties concerning the freedom of movement of people allow workers from this sector to work in Switzerland for up to 90 days.
"The existing agreements on the free movement of people are static," Swiss EU Integration Office spokesman Adrian Sollberger told swissinfo.
"If there is movement in certain areas that are covered by this agreement, such as opening up the market in services, then Switzerland is free to decide whether to take over new EU regulations in the sector covered by this agreement or not."
Sollberger added that the Swiss government would only consider re-entering negotiations on the service sector after seeing the contents of an extensive report looking into all aspects of EU relations being written for the summer.
swissinfo, Matthew Allen
Switzerland has bilateral treaties with the EU guaranteeing the freedom of movement of workers across borders.
However, Switzerland imposed quotas for the number of labourers from eastern Europe until at least 2011, and possibly until 2014, when the agreement was extended to the new EU states in September last year.
Switzerland also hired 150 labour inspectors to guard against wage dumping.
The EU Services Directive aims to remove legal and administrative barriers that can hinder businesses from offering their services in other countries in the EU.
Businesses covered in the directive range from hotels and restaurants to construction, car hire, advertising, estate agencies and services offered by professionals such as architects and lawyers.
EU leaders ordered the original directive to be changed in March last year amid fears it could result in domestic companies being priced out of the market by cheaper foreign firms.
Switzerland would not be bound by the directive as its previous labour accords are binding and static.
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