Swiss voters have clearly backed the extension of a labour accord with the European Union to the ten new EU member states.
Final results showed both the German- and French-speaking areas of the country had approved the treaty in voting on Sunday, while the Italian part said "no".
Only seven of the country's 26 cantons said "no" to extending the free movement of people accord, including the Italian-speaking Ticino region.
Approval of the accord was particularly strong in western Switzerland.
According to exit polls conducted by the gfs.bern polling institute for the Swiss Broadcasting Corporation, 56 per cent of voters approved the accord with 44 per cent against.
Turnout was above average at around 56 per cent.
Supporters say opening up the labour market will result in economic growth, while opponents argue it will lead to a flood of immigrants.
Bern and Brussels concluded a first set of treaties in 1999, which included a gradual opening up of their respective labour markets. The deal came into force in 2002.
With the enlargement of the EU to 25 members in 2004 Switzerland had to negotiate an agreement with the ten new members, mainly eastern European countries.
The Swiss parliament approved the deal, but small parties on the far-right and left of the political spectrum challenged the decision to a nationwide vote. They were supported by the rightwing Swiss People's Party.
Under the accord, Switzerland and the new EU member countries would grant mutual access to their labour markets but only after a period of transition which would include the use of quotas.
Parliament has also endorsed a set of additional measures aimed at preventing a massive influx of cheap labour from undercutting salary levels.
Boost or threat?
Supporters of the free movement of people said the labour accord would secure jobs in Switzerland and keep the country attractive for foreign investors and Swiss companies.
The government warned that rejection of the deal would damage Switzerland's image and seriously hinder the country's export-driven economy.
The business community, the trade unions and three of the four leading parties all came out in favour of the accord.
Opponents expressed fears about rising unemployment, currently at 3.6 per cent, if Switzerland opens its market to the 75 million citizens from the new EU member countries.
There were also widespread concerns about salary dumping as a result of increased competition and that the country's social-security system could become overburdened.
A labour accord between Switzerland and the EU is to be gradually extended to the ten new member states in eastern Europe.
The group is made up of the three Baltic republics (Latvia, Lithuania, Estonia), Poland, the Czech Republic, Slovakia, Hungary, Slovenia, Malta and Cyprus.
The Swiss parliament also approved a series of measures to prevent salary dumping and an undercutting of labour standards.
1992: Swiss voters reject European Economic Area Treaty.
1997: Electorate rejects proposal for nationwide vote on membership negotiations and withdrawal of request for membership talks.
2000: Swiss voters approve first set of bilateral accords with EU.
2001: Rejection of proposal to launch full EU membership negotiations.
2005: Voters approve closer police cooperation with EU (Schengen/Dublin accords) as part of bilateral accords II.