English is a second language for 1 in 8 pupils in England

The Government survey highlights the 'disunited nations' in classrooms as teachers battle to educate a massive influx of immigrants. In some areas more than 70 per cent of pupils arriving at the school gates do not speak English as their mother tongue.

MPs and unions immediately called on ministers to take urgent action to prevent primaries and secondaries being overwhelmed by the pressure. They warn that schools are being forced to juggle resources as migrant children take longer to understand lessons and divert the teacher's energies from other pupils.

The figures give the sharpest snapshot yet of the scale of the challenge facing schools around the country.

The Department for Children, Schools and Families statistics showed that 815,450 schoolchildren  -  or 12.5 per cent  -  did not speak English as their mother tongue as of January this year.

For primary schools, the proportion was 14.3 per cent, or one in seven, compared with 10.5 per cent in 2004, the year before European Union expansion.

Meanwhile, in secondary schools 10.6 per cent of pupils, or about 450,000, have English as a second language. Two years ago, the proportion was 9.5 per cent.

Some 240 different languages were spoken in England's schools, according to the department. In the first breakdown of the different tongues, it was revealed that 102,570 pupils are native Punjabi speakers.

The department's annual census showed that more than 85,000 children spoke Urdu, 70,320 spoke Bengali, 32,030 used Somali at home and there were 26,840 pupils whose primary language is Polish.

It is not uncommon to find schools where there are more than 50 languages spoken.

Children with English as a second language are a minority in around 1,300 of the country's 21,000 primaries and secondaries.

Teachers' leaders said that if schools are not given more money to help them cope with foreign speakers, it could lead to severe problems in the classroom.

Towns and cities which had seen a sharp increase in recent years were likely to be hardest hit, and teachers in these areas needed special help to manage the influx.

Some schools have launched drives to recruit bilingual teaching assistants to help out. Philip Parkin, general secretary of Voice, formerly the Professional Association of Teachers, said: 'We want childrens' experience of school to be enjoyable and often non-English speakers are the most motivated and quickest to learn.

'But when you have one child coming into the classroom who doesn't speak English, it makes it very, very difficult for teachers. If you have more than one, that becomes a huge headache. There is also a concern that resources have to be spread too thinly in the classroom.'

Damian Green, the Tory immigration spokesman, said schools are being let down by the Government because ministers do not have a clue who is arriving in Britain. He added: 'In the long run we have got to get proper control of our immigration system.'

Mick Brookes, of the Association of Teachers and Lecturers, stressed recently that schools welcome new arrivals but often lack resources to integrate them properly.

He said: 'Unless this is addressed, some schools could reach breaking point.' The cost of educating a non-English-speaking primary pupil is estimated at £30,000 a year, compared with £4,000 for a native speaker.

Schools Minister Jim Knight said: 'It is fatuous and completely out of touch to claim that this is causing rifts in classrooms. Schools will always have and always will teach in English.

'There is record investment going into schools, so every child gets up to speed quickly in reading, writing and speaking.'

A schools department spokesman pointed out that a child's first language is defined as the one to which they were initially exposed. Even if they are proficient in English, it will be classed as their second language.