The Swiss Senate has approved a new law on foreign nationals, opening the door to citizens of the European Union and the European Free Trade Association.
But the new legislation will only allow qualified workers from outside these zones to immigrate to Switzerland.
The law reaffirms current two-tier immigration practices. Only a few thousand foreigners from outside the EU and EFTA are allowed to come and work in Switzerland each year.
Citizens from Europe's two major trading blocs benefit from a free movement of labour accord with Switzerland that does not limit their job opportunities or residency rights.
But the new legislation does not include any provision for seasonal workers from outside the EU and EFTA zones. Seasonal work permits have not been given out since the application of the free movement of labour accord in 2002.
The law, which lays down clearly for the first time the principles and objectives of the integration of foreign nationals and replaces 1931 legislation, also changes some residency rules.
Foreign nationals will no longer be granted permanent resident status automatically after ten years in Switzerland. The cantons will be asked to review each request for permanent residence.
Families will also find it harder to be reunited in Switzerland. For example, children of the foreign spouse of a Swiss national will now not be granted long-term residency if they are over the age of 12, versus 14 previously.
The government announced in September plans to improve integration of foreign nationals. Anyone applying for a residence permit could soon face compulsory language courses.
Under these rules, the authorities will have to take into consideration the degree of integration of the applicant when granting a residence permit or permit extension.
Previously these conditions only applied to applications for citizenship.
The justice ministry said these requirements would also apply to those who give religious instruction, culture or language classes within foreign communities.
The new legislation voted by the Senate increases the amount of time a person who has contravened the laws on asylum or foreign nationals can be detained from one to two years.
Access to some areas could also be restricted for foreigners who threaten law and order. This measure is aimed particularly at people involved in drug trafficking, but could also be applied to asylum seekers whose applications have been rejected and have not left the country.
swissinfo with agencies
At the end of 2003, there were approximately 1.5 million foreigners living in Switzerland, or around 20 per cent of the population.
54 per cent were citizens of the EU or EFTA nationals.
42 per cent were immigrants from other parts of the world.
Just four per cent of the foreign population is made up of asylum seekers.