As children return to school across Wales, more than 700 staff are still awaiting security checks which will allow them to enter the classroom.

Some schools have said they may have to send children home because of the delays.

Head teachers and governors are concerned that assurances by the Criminal Records Bureau that all checks on staff would be complete by 4 September have not been fulfilled.

Schools are concerned by the disruption

Voluntary organisations such as St John Ambulance, have also raised concerns over delays on checking their own staff.

The Home Office admitted on Sunday that 7,000 checks on staff in the UK would not be completed by Wednesday.

The checks are meant to be a "one-stop-shop" to process criminal records and checks against government blacklists of people not suitable to work with children.

They must be carried out before teachers and support staff can work with children.

We have been telling the Home Office for months that this situation was avoidable.

Karl Davies, NAHT

In Cardiff, 126 teachers are still waiting to be cleared for work.

The checks on teachers have been brought in by the UK Government and come in the wake of the deaths of Cambridgeshire school children Holly Wells and Jessica Chapman.

Karl Davies, director of the National Association of Head teachers in Wales, said the CRB procedure delays were not acceptable.

He said there should be no need for pupils to be sent home at schools where staff checks were incomplete, which has happened at some schools in England.

Criminal Records Bureau: Lengthy delays

But Mr Davies added schools affected in Wales would have to be creative with their teaching rotas to deal with the situation.

"It is something that is avoidable. We have been telling the Home Office for months that this situation was avoidable.

"Whereas until recently schools were able to check staff against List 99 - those people who have been convicted of an offence - the government said further checks were necessary.

"What we want to see at the beginning of the first term of the year is a good start for teachers and pupils."

We are stockpiling problems

Keith Dunn, St John Ambulance

John Dunford, general secretary the Secondary Heads Association, said it was a very bad start to the new school year.

"This is a messy, avoidable crisis that we predicted a year ago and warned the government about."

Keith Dunn, of St John Ambulance, said the situation for voluntary groups was also becoming serious.

"We are very concerned at the delays taking place. We were told they would take three weeks and they are actually taking two months.

"We are stockpiling problems."

Catriona Williams, director of Children in Wales, added her concerns to the growing problem in Wales.

"This really does need sorting out. There are a large number of people that have yet to undergo checks."