W hen Civitas, the right-of-centre think-tank, started scouting possible locations to open its second, low-cost private school in London, the parental jungle drums started banging immediately and it received five instant applications for places that don't yet exist.

"There's no shortage of demand," says Robert Whelan, managing director of Civitas's New Model School Company, which owns and runs one primary but has plans to expand. "In fact, there's a level of desperation."