Asian pupils who would traditionally have received support from teachers of English as an Additional Language are being "squeezed out" to make way for Eastern European youngsters who often speak no English and are deemed to need the service more.
The shift in resources is having a detrimental effect on the education of Scots-born Asian pupils, according to Larry Flanagan, principal teacher of English and drama at Hillhead High in Glasgow, where 35-40 per cent of pupils are from ethnic minority backgrounds.
Bilingual Asian youngsters can have good conversational skills in their second language, English, he argued. But some struggle to take their English to a more "sophisticated" level because the language they speak at home is purely oral and they do not have "paper skills" - reading, writing and sentence structure - on which to build.
"These pupils' oral competency in English means they can survive in the school environment in terms of speaking and understanding instructions, but cannot access the curriculum, as most of it is written."
In Glasgow secondary schools such as Hillhead, Bellahouston and Shawlands, which have large multicultural populations, this was reflected in a "disproportionate number" of Asian pupils in Access 3 English classes, as opposed to Higher English, he said.
Eastern European pupils were also being let down by the Government's failure to invest in EAL support, he claimed.
Yulia, an S5 pupil at Hillhead, arrived in Scotland four years ago, unable to speak any English but fluent in Ukranian and Russian. She received EAL support for five months and is now sitting Higher English. If she arrived today, she would be lucky to receive 10 weeks of support, Mr Flanagan estimated.
"Fiona Hyslop has spoken about the importance of immigration to the Scottish economy," he told those gathered for his seminar at the Scottish Learning Festival in Glasgow last month. "Most people who come here, come here by invitation. If you are going to ask people to contribute to the economy, you have to accept responsibility in terms of what you provide for their families."
Some Pounds 9 million had been set aside for language support for adults, he said, but "not one penny" for children.
He was critical of the approach taken in Glasgow where, he said, the council was "covering up the cracks" by taking the same number of EAL teachers and spreading them across a number of schools.
The aim should not just be to increase the number of EAL staff in schools, he said. Teachers should up-skill and use the continuing professional development time available to them to learn how to cope with bilingual children in their classrooms, he urged.
Mr Flanagan found himself resorting to mime when Polish twins, who could not speak a word of English, joined his S2 English class last year. "Everyone needs to have some idea of how they are going to cope, because EAL is only there a certain percentage of the time and, at the moment, that's very small."
One delegate, a Glasgow-based EAL teacher, said pupils needed to know they could access help on a daily basis. Having been based in one of the city's schools, she was now split between two, she said - and it was not working.
"You need to be there every day so they know you are there if they don't understand, and they can approach you," she said.