By Imogen Foulkes
BBC correspondent in Bern
The United Nations refugee agency (UNHCR) has warned Switzerland that proposed changes to its asylum laws could breach the 1951 UN Convention on Refugees.
The Swiss government is currently considering proposals to deny access to the asylum procedure to applicants who cannot produce valid identity documents within 48 hours.
Asylum seekers could be forced to produce documents in 48 hours
The UNHCR has a number of concerns about the planned changes, but is most worried by the proposal on identity documents.
Many refugees flee their countries without papers; sometimes they have been confiscated by the authorities. Others never had identity cards in the first place.
Some asylum-seekers give their papers to unscrupulous people-smugglers to help them across borders and never get them back again.
All such cases deserve to have their requests for asylum heard, the agency says, even if they do not have valid documents.
The Swiss proposal to limit the time allowed to produce identity papers to 48 hours could, the UN believes, lead to people being forcibly returned to countries where they have been persecuted.
The refugee agency points out that applications for asylum are falling all over Europe, including Switzerland, and says there is no need for governments to focus so single-mindedly on restricting the asylum process.
But Switzerland's traditionally generous refugee policy is now in the hands of the far-right Justice Minister, Christoph Blocher, who came to office in December on a promise to crack down on illegal asylum-seekers.
Mr Blocher is famous for his determination to push his policies through. He also opposes what he sees as UN interference in Swiss affairs.
So he is unlikely to change his plans at the request of the UN refugee agency.