The number of "super primaries" across England is set to explode as local authorities struggle to deal with the sudden jump in pupil numbers, The TES can reveal.
A new generation of super-sized schools is currently in development, with some even welcoming six forms to their reception year this September.
Official figures show that 4 per cent of primary children are now taught in a school with more than 600 pupils, and this trend is set to accelerate. The total number of primary-age children across England is to jump nearly 400,000 to 4,409,000 in 2014.
This week Education Secretary Michael Gove said he would give new academies the right to expand to any size they like as long as there is parental demand. Cuckoo Hall Academy in Enfield was already in the process of expanding from 730 to 1,000 pupils when it gained its new status this year.
Local authorities are putting in place plans to deal with the hike in pupil numbers by expanding existing schools. Birmingham enlarged nine primaries this year and will swell a further 23 next year. Nine per cent already have more than 600 pupils.
One primary in the city, Starbank, welcomed six forms in reception this year, up from three, with some housed in temporary buildings in its playground.
Head Gerry Hudson said: "We were asked to do this about 15 months in advance. There is a real problem in this area with insufficient places.
"If the authority didn't do anything about it there would have been children out of school."
Last week the Department for Education published figures showing that 41,680 pupils nationwide were being taught in schools which took them on despite being full.
Another council, Richmond upon Thames, told The TES that there was no option but to expand its schools because of land restrictions.
And Southampton is due to start consulting on proposals to expand eight of its 61 primary sector schools in 2011 and a further 11 or 12 the following year.
The jump in large primaries was attacked by Mervyn Benford of the National Association for Small Schools. "Some people argue there is nowhere else to put these children, but we should be providing small schools in urban areas," he said. "That would be the real answer."