The government has been warned not to cut corners in the rush to clear a backlog of police checks on new school staff.

Delays in the vetting process have meant an extra 100 staff have been taken on at the new checking agency, the Criminal Records Bureau (CRB).

The total backlog stands at 100,000 - but not all of these are staff who must be available for work immediately term begins, said officials at the Department for Education and Skills.

It insisted that 25,000 new staff who must be available for the start of the autumn term in schools in England and Wales will have been checked.

'Warned before'

The Conservative party spokesman David Davis said nothing would have been done at all had it not been for the murders of Jessica Chapman and Holly Wells.

"It's dreadful that it takes a tragedy to bring the Home Office and the Department of Education to actually do the right thing," he said.

Labour's Liverpool Riverside MP Louise Ellman said the head of the CRB had written to her one month ago acknowledging "teething problems" and promising a range of improvements to clear the backlog.

She said it was "disappointing" it had taken the tragedy to focus public attention on the issue.

And Liberal Democrat home affairs spokesman Simon Hughes MP said the government had been warned "time and time again" about the backlog.

"Yet again the Home Office is reacting to a crisis of its own making," he said.

'No guarantee'

Head teachers fear their schools could be thrown into chaos this September, with not all school staff getting full clearance to work with children.

Heads have warned that other members of staff may have to cover vacancies until the checks are completed.

Gill Woollands is still waiting to hear if she can take up a teaching post in September

"It would not be a very good start to the autumn term," warned David Hart, general secretary of the National Association of Head Teachers.

"Clearly we welcome any measure which clears the backlog however late it may be.

"But heads still have no guarantee that staff they have appointed for September will receive complete clearance."

Strict checks

Teachers and other school staff have to undergo a double clearance before they can work with or near children.

The names of all school staff must be checked against a secret Department of Education dossier of people convicted or suspected of child abuse, called List 99, and they must also have their criminal records examined.

People will not be entering schools without those checks having been done

Department for Education

Education minister Margaret Hodge has insisted that checks on the staff most urgently needed would be completed by the start of term.

"We have got to ensure that those 25,000 who are in the process of being vetted are properly vetted," said Mrs Hodge.

"I hope that with these additional staff and resources, they won't have a problem."

The Department for Education stressed that no-one would be able to start work without being cleared.

"People will not be entering schools without those checks having been done and we are very clear on this," a spokesman said.

"There is no question of us compromising child safety."

Waiting game

Gill Woollands is one of those 25,000 still waiting to hear if she will be cleared to take up a new teaching post.

"I'd like to know that I can start next week. I've done what I can - I've sent the papers that I need to and I've filled in the forms that I need to," said Ms Woollands.

"I hope to be starting without any fuss next week, but unfortunately that won't be the case."

Until she is given the all-clear, her head teacher will have to take her class.