Children with English as their first language are in the minority in more than 1,300 schools, according to official figures.

Data from the Department for Children, Schools and Families (DCSF) obtained by the Daily Telegraph shows that in 1,338 primary and secondary schools in England there are fewer children with English as their first language than those who consider it a second language.

There are currently 17,361 primary schools in England and 3,343 secondary schools.

In 600 of these schools, less than a third of pupils speak English as their first language.

The figures led to warnings about the pressure that the number of children with English as a second language places on schools and teachers.

Coping with large numbers of foreign children risked undermining the quality of teaching given to all pupils, critics say.

The general secretary of the Professional Association of Teachers, Philip Parkin, said rising levels of immigration and a lack of multi-lingual teaching staff were "providing serious challenges" for schools trying to maintain standards.

"Dealing with non-English-speaking children makes it much harder to deliver the curriculum," he said.

Parkin added: "Schools that are in that position need considerable support in order to give those children help with English and help with our curriculum. "The government needs to be looking at funding the employment of teachers or teaching assistants, in addition to the staff they have, who are bilingual or multilingual."

Last month, the general secretary National Association of Head Teachers, Mick Brookes, told a Lords committee that some schools were struggling to cope with the influx of foreign pupils.

Brookes told the Telegraph that the latest figures proved the case for putting additional resources into the areas dealing with large numbers of non-English speakers.

"These children may not just need support to speak English, but often they require counselling to talk them through the trauma they have witnessed," he said.

DCSF data show that in 574 of the 17,361 primary schools in England, children without English as a first language make up between 51% and 70% of all pupils.

Another 569 primaries have more than 70% who count English as a second language.

In 112 of the 3,343 secondary schools, children without English as a first language make up 51% to 70% of all pupils and the proportion is more than 70% in another 83 secondary schools.

Children with English as a second language are particularly concentrated in London.

In the London borough of Newham, nine out of 10 schools most children have English as a second language.

Newham council's lead member for children and young people, the Rev Quintin Peppiatt, said: "In Newham, we celebrate the fact that we are the most culturally diverse place in the country. We believe that children who can speak different languages are an asset to the borough and contribute towards what makes it such a unique place to live.

"We tend to find that children who start school speaking little or no English learn the language very quickly. Socialising in the playground and outside of school also encourages a greater understanding and acceptance of cultural differences from an early age. We have heard teachers say that one of the main reasons they chose to work in Newham is because of this diversity."

Tom Canning, head of Tollgate primary school in Newham, said the 42 languages spoken by more than 70% of the children in his school was a plus. "The diversity of our community here in Newham is probably one of our greatest strengths. Bilingual children have a good grasp of their mother tongue and learn English very quickly with great support from parents. It's good for all our children because it gives them a different viewpoint on the world that they wouldn't have otherwise."

Canning said the influx of children with English as a second language was not a new phenomenon. "We have to move away from this as somehow dumbing down our schools. It's not at all. Lots of schools in London with 70% or 80% of children with English as a second language are beating the national average. I see it as a very positive picture rather than a bleak one."

The Association of Teachers and Lecturers acting deputy general secretary, Martin Johnson, said: "We are not surprised by these findings. The majority of these areas have a history of succeeding waves of migration and as a result the schools are well used to coping with children with different mother tongues. They get the ethnic minority funding grant to help fund bilingual staff and teaching materials where necessary. And from April there will be an exceptional circumstances grant to draw upon when needed.

"Overall these schools are not disadvantaged by having multi-language groups - instead many of the new comers are highly motivated and keen to succeed at school. However, some schools will be disadvantaged by other problems some of these children have - poverty, high mobility, trauma from the dangers of their previous life - all of which can have a significant impact on their ability to learn."

The National Primary Heads Association chairman, Peter Price, said: "There are difficulties and the older the child is the more difficult it is when they lack proper communication skills. But very young children absorb language and it's of benefit to English speaking children to learn other languages from classmates they sit alongside."

He said involving parents of children with English as a second language was also beneficial to the community and schools.

But the variety of languages coming into a single school could be "extremely difficult for a teacher to cope with" especially when they are already under pressure to raise standards and attainment.

"Without additional resources schools will struggle. Schools need financial help and the support of linguists. But people shouldn't overlook the benefits. Celebrating different cultures is very rewarding," Price added.

A DCSF spokesman said local authorities received funding through the Ethnic Minority Achievement Grant, which is set to increase from £179m in 2007-08 to £207m by 2010-11.

He said funding is allocated according to pupil numbers, adding: "A new arrivals excellence programme has been established and in addition, from 2008-09 local authorities which experience significant, mid-year influxes of pupils, or of pupils with English as an additional language will be eligible for a top-up to their core funding through the new Exceptional Circumstances Grant."