Revelations that sex offenders have been given clearance to carry on teaching have shocked parents and threatened a Cabinet minister's career. Nick Morrison looks at calls for reassurance that children are not being put at risk.

IT started slowly, with the news that a PE teacher who had been placed on the sex offenders' register had been allowed to continue teaching. Paul Reeve had been cautioned for looking at banned pictures of children on the internet but questions over the evidence clouded the issue of whether he should have been automatically banned from the classroom.

But it quickly snowballed. First with the revelation that "about ten" people on the register have been given permission to teach, as much for the uncertainty as for the number itself. Then details of two further cases emerged, with the likelihood that more are on their way.

One concerned a teacher who had been convicted of a sexual offence at a school in the North-East. William Gibson was teaching physics in Sunderland when he was convicted of indecently assaulting the 15-year-old in 1980.

Despite his conviction, and subsequent convictions for fraud, he went on to teach at schools in South Tyneside and County Durham before getting a post teaching maths in Dorset. He was suspended when details of his past came to light.

The assumption that sex offenders would automatically be banned from working with children has been shattered. Instead, it appeared that ministers could use their discretion to allow those on the sex offenders' register to stay in the classroom.

Moreover, holes in the existing set-up had already been revealed by the inquiry into the Soham killings, which recommended that there should be a single list of those not allowed to work with children.

Under mounting pressure, the Government announced an urgent review into the way people are cleared to teach. Education Secretary Ruth Kelly is due to make a statement on the issue on Thursday, but already it has been revealed that ministers will be stripped of their discretionary powers, which instead would be passed onto independent experts.

But some would like the review to go further, and to automatically exclude everyone on the register from teaching. Under the existing system, teachers can be cleared to work in a school once they have been put through what is known as a List 99 check. List 99 contains the names of people banned from working with children, but does not necessarily tally with the sex offenders' register: being on the register does not automatically mean you are on List 99.

Appointments made on the basis of List 99 and pending a Criminal Records Bureau (CRB) check, means some sex offenders could be teaching for months before the CRB check comes through. This is inadequate and a source of serious concern among parents, according to Margaret Morrissey, spokeswoman for the National Confederation of Parent Teacher Associations.

"Parents need an absolute guarantee that those people who are on the sex offenders' register would be stopped immediately from teaching," she says. One drawback is the possibility that someone may be on the register after having accepted a caution, but the evidence against them may be far from conclusive and they may have chosen a caution ahead of a traumatic court ordeal.

But this is not the issue for most parents, says Ms Morrissey. Instead, it is purely about making sure children are as safe as possible. "We're not here to say who should and shouldn't be on the sex offenders' register, but people on the register at some point are considered a risk to our children and it is just not acceptable to allow them to continue teaching," she says.

In a further example of the exercise of ministerial discretion, a teacher considered to pose a risk to young boys was allowed to teach provided it was at all-girl schools. Medical evidence suggested Keith Hudson had "paedophilic and inappropriate" feelings towards young boys, and, while he was on List 99, he was said to have no interest in girls and was cleared to work in girls' schools.

Ms Morrissey calls this suggestion "disgusting", reinforcing the view that a ban should be automatic, but equally appalling is that the Education Secretary has been so far unable to give a definitive figure of how many times this discretion has been used.

"It is unbelievable that there are no checks - if there were regular checks and updates she would know, and as time has unfolded it has got even more confused," she says.

But the existence of grey areas is something that troubles Dorothy Elliott, chair of governors of Portland Special School in Sunderland and executive member of the National Governors' Council. "As governors, we are always concerned that our children are educated in a safe and secure environment," she says. "And I would hope that whatever changes are made are to protect the children.

"Yet we have grey areas where it is very difficult to make a hard and fast decision, and in many cases one size doesn't fit all. At the same time, we have to make sure we don't include someone who is an inappropriate person. It is a very difficult issue."

There is also a danger, she says, that the controversy will dent parents' confidence in the entire teaching profession. This is also a concern to Mick Lyons, North-East executive member of the teaching union, Nasuwt. He believes that, serious though the problem is, it is important to keep it in proportion.

"They have found about ten people out of half a million teachers, and if you look at in perspective some of the coverage has been a touch over the top," he says. "I would not like to see a major witch-hunt and I would be disappointed if there were major changes just to keep Ms Kelly's job.

"Obviously parents have a right to know their children are being taught in a safe environment but the current climate is probably not the time to be pushing through emergency legislation. We should wait until the furore has died down and look at it in the cold light of day."

The Government's anxiety to stem the tide of damaging revelations means this will probably go unheeded, and legislation planned for the summer is now likely to be brought forward within a month, but Mr Lyons counsels against assuming that a one-size-fits-all policy is the best approach.

"We have got a system where every case is looked at on its own merits, but would it be right to go to the other end of the scale where absolutely everybody should be barred full stop?," he says. "I don't know if there is one solution to every single case.

"I appreciate the concerns people have and we can't allow children to be put in a position where they could be vulnerable, but we have still got to look at being fair. A lot of people would say that if you are a sex offender you are not entitled to fair treatment, but if it has been alleged but not proved what happens then?"

For Ms Kelly, the crunch comes on Thursday when she announces the results of the review. Although it is difficult to consider what she could say to satisfy her critics, she may yet hang onto her job. For parents, the key will be whether a new system will provide the safeguards they are demanding to ensure that sex offenders are not allowed in the classroom.