Scottish teachers are having to cope with unprecedented numbers of pupils who have difficulty speaking English following a sharp increase in immigrants and asylum seekers.

The Scottish Government was last night facing urgent calls to provide more funding to train language support specialists after new figures showed the number of pupils not fluent in English rose by 62.5% between 2006 and 2007 from 9486 to 15,411. Of these, 3595 had no English at all.

The figures reflect growing immigration into Scotland in recent years with a net population boost of 12,000 in 2006 alone - the largest since 1999.

All but three of the country's 32 local authorities have experienced an increase in pupils whose main language is not English, though Edinburgh and Glasgow have seen the greatest rise.

The most significant numbers of new immigrants come from Poland, with Polish now the second most commonly spoken language after English in 16 local authority areas. Punjabi, Urdu, Cantonese and Arabic are also common.

Teachers argue the increases have been so rapid that demand for language support teachers is fast outstripping supply. There are only 206 registered teachers with the necessary qualification in secondary schools. Figures are not available for primaries.

The government argues that funding from the Scottish Budget to local authorities is sufficient to provide for the support needed.

Yesterday's figures also show the scale of the task facing local authorities to meet the Scottish Government's commitments to reduce class sizes in the first three years of primary to just 18.

Councils have been asked to move towards the target "as quickly as possible", but the Pupils in Scotland 2007 report, published yesterday by the government, shows that though class sizes in primary have fallen, just 12% of P1-P3 pupils are in classes of 18 or fewer.

On the influx of new migrants, Ronnie Smith, general secretary of the Educational Institute of Scotland, said extra money was needed from central government to support the work of teachers.

"Teachers and pupils welcome these young people, but there is a desperate need for additional support to allow these children to make the most of their education," he said Greg Dempster, general secretary of the Association of Headteachers and Deputes in Scotland, which represents primary heads, echoed the call.

"The overall increase of 60% masks the fact that, in some schools, headteachers have seen increases of 200% in the proportion of these children, which puts a real strain on a school's capacity to deliver education.

"No council is swimming in money and it will be very hard to find funding for this at local level - that has to be recognised by the national government."

John Stodter, general secretary of the Association of Directors of Education Scotland, which represents senior council education officials, warned: "There has been no increased resources to councils on this issue and we need to have a look at where the pressure points are at school and council level," he said.

"When that has been done we can use the partnership that exists between councils and the government to identify the gaps in resources and pull together a national strategy for addressing these challenges."

A Scottish Government spokeswoman said: "Under the Budget agreement with local authorities there should be sufficient money to deal with these issues."