Gaining Swiss citizenship remains a highly controversial issue following the latest round of debate in parliament.
The House of Representatives insisted on Tuesday that applications for naturalisation should not be decided by local ballot box votes. The Senate, however, wants to allow such decisions if the right of appeal is guaranteed.
The proposal is a compromise to an initiative by the rightwing Swiss People's Party for "democratic naturalisations". The initiative wants citizens to have the final say in voting on citizenship applications, instead of leaving it up to an elected local body.
This procedure has been subject to heated criticism and media attention in recent years, notably when voters in the town of Emmen in central Switzerland repeatedly rejected the naturalisation of foreigners, especially those from the Balkans.
In 2003 the Federal Court effectively banned local ballot box decisions on naturalisations saying they were unconstitutional.
"We do not want naturalisation to be a purely administrative procedure. It should remain a political but not arbitrary act," said Thérèse Meyer of the centre-right Christian Democratic Party.
The House narrowly voted in favour of maintaining the status quo, where an elected communal commission decides whether a foreign applicant receives a Swiss passport, rather than local people.
According to Isabelle Moret of the centre-right Radical Party, the danger of naturalisations at the ballot box was that they lead to people "taking decisions based on the colour of someone's skin".
The House also agreed that the cantons should publish certain details on the candidates for citizenship, such as their religious affiliation. But the People's Party failed to extend this to information such as whether the person receives social welfare, if they have paid their taxes or have debts.
"This kind of information can be provided orally, if necessary," said Kurt Fluri, from the Radical Party.
Reasons for rejection
The debate also centred on explaining to rejected applicants why exactly they were turned down. Parliamentarians supported the idea of providing clear written explanations to foreign applicants.
But Jasmin Hutter of the People's Party attacked this procedure: "The decisions of the people should be respected without being questioned."
If an application is rejected, the foreign candidate can still appeal to the cantonal law courts.
The People's Party failed in its attempt to include a right to appeal against naturalisations that had already been granted.
The compromise vote now passes back to the Senate.
swissinfo with agencies
There are 500,000 people born to immigrant parents in Switzerland.
About one-third have become Swiss nationals.
A first-generation immigrant is someone who has moved to Switzerland, after being born elsewhere.
A second-generation immigrant is born to first-generation immigrants.
Foreign residents must wait at least 12 years before being eligible to apply for citizenship, compared with between four and ten years in European Union states.
In most EU countries it is easier for children born to foreign residents to become naturalised than it is in Switzerland.
Foreigners married to Swiss nationals can take advantage of a simplified or "facilitated" procedure, reducing the number of years they have to wait (see related site, Federal Migration Office).
Successful applicants must show that they are integrated into Swiss society, comply with Swiss law and pose no threat to internal or external security.
The cantonal and local authorities are responsible for naturalisation procedures.
In 2006, 47,607 applications were accepted.
There are 1.5 million foreigners currently living in Switzerland, out of a total population of 7.5 million people.