The rising numbers of foreign workers arriving in Switzerland are finding it increasingly difficult to find places for their children in international schools.
The surging demand has focussed on well-established learning centres that have been forced to expand. But smaller and newly built schools are offering alternatives to children stuck in waiting lists.
Zurich International School (ZIS) is still over-subscribed despite building a new SFr36 million ($32 million) campus for older students this year. The school expected the campus to open with 350 pupils, but has already reached its capacity of 450.
"We have been a bit surprised by the rapid growth rate of 15-20 per cent of new students in each of the past two years. If that continues, unless we get new infrastructure we are going to face a minor crisis at international schools," director Peter Mott told swissinfo.
"For some of those families on their way to Switzerland or in the country the situation is desperate. We receive calls daily asking us to help out but we have to maintain the quality of our programmes."
The reason for the sudden surge in demand for school places is the recent influx of highly skilled employees from abroad, hired to fill positions at expanding Swiss firms. This has been aided by Switzerland's bilateral accord with the European Union that has opened borders to workers.
Swiss cantons have also continued to persuade international companies to relocate their headquarters to Switzerland with the lure of low tax rates.
ZIS is not the only international school to come under pressure to find more places for pupils. The Intercommunity School Zurich has turned away hundreds of students over the past year, and the pressure is being felt elsewhere around Switzerland.
The International School of Winterthur, about 30 kilometres from Zurich, has relocated three times in the past six years to increase capacity. Voters in Schaffhausen have recently approved the relocation of its school for foreign students to bigger premises while the International School of Zug and Lucerne is oversubscribed and building new facilities.
Michaelene Stack, director of development at the International School of Geneva (4,000 capacity), told swissinfo that demand is just as strong in the west of Switzerland.
"We had unprecedented levels of requests for places at the start of this academic year – more than we had places for – and we see no signs of that abating," she said. A new campus offering 1,000 new places is already full just four years after it was opened, she added.
ZIS director Mott warned that some Swiss business centres might lose their attractiveness if foreign employees cannot find the right educational facilities for their children. He called on the cantons for financial assistance to help them expand.
"Highly qualified people will not come to Switzerland unless their children can be guaranteed a place at an international school," he said.
But Daniel Sarbach, director of the Swiss International School Zurich North, said there were still places to be had in smaller schools.
"Parents tend to follow the recommendations of work colleagues which focuses demand on a few larger schools," he told swissinfo. "But if the demand for places is diversified to other schools then many more pupils can be accommodated."
As if to illustrate his point, an international school recently opened in Fribourg without a single pupil being registered. But its director was adamant that places would be filled once people became aware of its existence.
swissinfo, Matthew Allen in Zurich
The Swiss Group of International Schools (SGIS) is the umbrella organisation for educational establishments for foreign students in Switzerland.
The organisation has 40 school members from all over Switzerland.
It provides details of international schools, provides a platform for such institutions and represents their interests in Switzerland.
The larger schools typically provide education for children aged from three to 19 and many offer the International Baccalaureate.
International schools in Switzerland can attract pupils from 50 or more nationalities.