English schools will need to find almost 420,000 extra school places over the next decade, due in part to a baby boom among migrant mothers.
The Department for Education has reported that, while its latest projections suggest that 'Direct immigration of pupils born outside the UK has a very small effect on the school age population' compared to the birth rate, the birth rate 'is in turn affected by any increase in the number of children born to non-UK born women (who overall tend to have higher fertility rates).'
A document explaining underlying methodology of the new figures explain that 'Changes in the population who are of school age is largely driven by an increase in the birth rate rather than direct immigration,' for the most part, but 'that birth rate is in turn affected by any increase in the number of children born to non-UK born women (compared to those born to non UK-born women).'
'The number of children born to non-UK born women increased by around 75 per cent between 2002 and 2013 (the years in which many children currently in schools were born),' the Government document adds - although it appears to make some effort to play the figure down by suggesting that 'this was a period of increased births generally.'
Neil Anderson, executive director of the Migration Watch UK think tank, appeared to suggest that the Department of Education was understating the scale of the challenge.
'Thousands of schools in England are bursting at the seams in the wake of the population boom, four-fifths of which has been driven since 2001 by massive levels of immigration.'
Mr Anderson said it was clear that 'The net arrival of 250,000 people per year cannot but have a huge impact on school capacity,' adding that it was 'high time the Government started to deal with the problem by delivering on their promise to reduce immigration.'
The Tory Party pledged to reduce net immigration 'from the hundreds of thousands to the tens of thousands' ahead of the last three general elections, but non-EU immigration - the only type of immigration the British government can largely control - has in fact reached a 15-year high.
Former Chancellor of the Exchequer George Osborne has suggested that this is because the Tory leadership is privately opposed to reducing net immigration, and never took any serious attempts to do so.