Schools in England and Wales are contacting new staff to tell them to come into work, even if security checks on their backgrounds are not complete.

The Education Secretary, Estelle Morris, changed the guidelines on Wednesday after admitting her strict vetting policy had caused disruption.

The move came after thousands of children were sent home at the start of term because their schools did not have enough teachers with the necessary clearance due to the backlog at the Criminal Records Bureau (CRB).

Some education authorities had defied the Department for Education's strict guidelines and let people start work provided they were supervised.

U-turn: Estelle Morris

Later, Ms Morris granted head teachers discretionary powers to use unvetted staff, after finding out the criminal checks would not be completed for weeks.

Her move was later endorsed by the Welsh Education Minister, Jane Davidson.

Ms Morris told BBC News she wanted to thank head teachers for taking on the responsibility for making the decision on who to allow to work in their schools.

She stressed: "It's not me saying, 'Nothing to do with me, guv' - whatever decision they take I will back them to the hilt on that."

Earlier she made clear her anger with the CRB and Capita, the firm running it under a Private Finance Initiative arrangement.

She said she had spoken to the Home Secretary, David Blunkett.

"Both of us are cross about this, and both of us over the coming days and weeks will be asking questions and making sure that the CRB is running as efficiently as it should be."

'Safer in school'

She apologised for the disruption but said it should not be used as a way to hammer the private sector.

The 7,000 staff awaiting the CRB checks will have undergone preliminary vetting checks against List 99 - a database of people deemed unsuitable to work with children - before they enter the classroom.

I think the blame is shared between the agency and the government in a situation which was entirely predictable and avoidable

John Dunford Secondary Heads Association

This week, head teachers following the original guidelines had to send children home because they did not have enough cleared staff to teach them.

The situation was attacked by teachers' leaders and child care experts, who said children were safer in school than on the streets.

The general secretary of the NASUWT teachers' union, Eamonn O'Kane, welcomed the U-turn and said it could have taken until Christmas for all teachers and teaching assistants to be cleared.

John Dunford, general secretary of the Secondary Heads Association, said: "I'm still not apportioning blame - I think the blame is shared between the agency and the government in a situation which was entirely predictable and avoidable."

I was not given assurances that made me confident that the present disruption to school would not continue for some time

Estelle Morris Education Secretary

The deputy general secretary of the Association of Teachers and Lecturers, Gwen Evans, said: "We welcome Estelle Morris's overdue rescue operation to bail out the Criminal Records Bureau which will repair some of the damage done by what appears to be the incompetence of the private sector contractor.

"It gives no satisfaction to remind government that we have been predicting this crisis for almost two years.

"There are lessons to be learnt from this fiasco across government. Taxpayers have a right to be sure that their money is being well spent on securing effective public services.

"This is a textbook illustration of all the reservations which ATL members have about the involvement of for profit companies in running public services.

Scotland and Northern Ireland

Liberal Democrat education spokesman Phil Willis said: "Having castigated heads and local authorities for allowing teachers to work without clearance, Estelle Morris has now confirmed they were right in the first place."

The CRB is supposed to process criminal record and List 99 checks on teachers within three weeks, but delays started to build up almost as soon as it opened in the spring.

A similar service in Scotland - known as Disclosure Scotland - is said to have been working without problems.

The system in Northern Ireland has not changed for years.

Employers obtain police checks from the Police Service for Northern Ireland, either directly, or through the Department of Education, or - in the case of supply agencies - through the Department of Health, Social Services and Public Safety.