All children in Switzerland have the right to education, but not all are receiving schooling, according to a new survey.
The survey, conducted in 17 cantons, found that the children of asylum seekers were not always offered places at state schools.
It also found a huge discrepancy between the French-speaking cantons and German areas when it came to the provision of education to foreign children.
While the right to education was recognised by all cantons, primarily German-speaking cantons were failing to abide by the terms of the UN Convention on the Rights of the Child.
The Swiss union of public service workers - which commissioned the survey - said the findings showed the need for a nationwide policy of admitting the children of asylum seekers to state schools.
Ruedi Tobler, a spokesman for the union and a member of a working group on intercultural education, said he was taken aback by the huge discrepancy between the French-speaking and German-speaking cantons on the issue of education for foreign children.
"Human rights are apparently well established in French-speaking Switzerland, while in German-speaking areas they are not adequately recognised," Tobler told swissinfo.
The union said that while French-speaking cantons abided by the UN convention, education policy in German-language areas tended to be governed by directives from the aliens' police.
Schools in some cantons could even be seen as aiding the work of the aliens' police, the union said, quoting the example of cantons Solothurn and Bern, where the police have the right to ask schools to hand over a list of names of all foreign pupils.
Tobler said this was happening despite the 1991 declaration by the Swiss conference of cantonal education departments that all foreign children should be integrated into state schools.
And he said it was time for the conference to take the initiative: "I hope it will react to the findings of our survey by renewing its recommendations."
The union said that in various parts of German-speaking Switzerland the children of asylum seekers were being kept out of school, in spite of the conference recommendations.
In Aarwangen, canton Bern, 12 foreign children are excluded from school. Aarwangen's deputy school director, Fritz Läng, said schools there were following a 1998 directive from the Bern education department that the children of asylum seekers be admitted to schools only when it was "sensible, appropriate and necessary" to do so, and when places were available.
In many cases, the policy of excluding asylum seekers' children from school was having a detrimental effect on the children's well being, according to the non-governmental organisation Solidarité sans frontiers.
The organisation's Anni Lanz recently visited two hostels for asylum seekers in Bern and spoke to children there.
"These young people are very confused," Lanz told swissinfo. "They want to learn, and without schooling their horizons are very limited."
Lanz warned that the children's alienation could lead to mental problems. "On the one hand they are seriously intellectually under taxed, and on the other there is a loss of boundaries."
swissinfo, Jean-Michel Berthoud
All Swiss cantons recognise the right to education for all children in principle, but there are huge differences in practice. German-language cantons tend to follow police directives on educating the children of asylum seekers, while schools in French-language areas accept asylum seekers' children unconditionally. The union of public sector workers is demanding a nationwide policy of extending schooling to all foreign children, regardless of the status of their parents.end of infobox