The country is paying a high price for a government decision to go soft on pupils caught taking drugs, Iain Duncan Smith has told the House of Commons.

The Tory leader asked the prime minister why Labour performed a U-turn on giving teachers the power to exclude children caught dealing drugs.

"In 1998 the prime minister removed the power of teachers to remove pupils involved in drugs, does he now regret that policy?" he asked.

Whilst Blair said he had tried to "bear down on unnecessary exclusions" he insisted headteachers still "had the power to exclude pupils that are causing a problem in their schools".

The Tory leader said that the government claimed in 1998 that excluding children who deal in drugs was "extreme".

"Drug dealing in schools has risen by a third since they came to power...and assaults on teachers have risen five-fold since they came to power," he said.

"Our schools are now more drug infested and violence ridden as a direct result of the government undermining headteachers."

Blair hit back saying that the government was not only giving headteachers new powers to exclude pupils caught dealing in drugs but was also dealing with the underlying problems of drug use.

He said the Tory attack "was a quite pathetic attempt to exploit.. a serious issues in schools".

"We know very well that the numbers of pupils taking drugs is a very serious issue in our schools," said Blair.

"But it is nonsense to suggest that we are saying that headteachers should not have the power to exclude pupils who are taking drugs."

"What is more, the work that we have been doing in schools on drug education, on ensuring that those that are dealing on drugs bears comparison with anything that the previous government did."