Russell Hobby from the National Association of Head Teachers said the "lack of planning is frustrating" when it comes to school places.
Speaking to Daybreak he said: "You should be able to predict this, when more children are born, four years later you need more school places."
More top news
Deputy Prime Minister Nick Clegg launched his election battlebus today with an attack on the Conservative Party.
The rain band will soon be clearing eastwards, but more showers will be affecting parts of the UK this afternoon.
David Cameron will stand down as Conservative leader ahead of the general election expected in 2020, Iain Duncan Smith said.