Widespread flaws in criminal vetting procedures for teachers and school support staff are exposed in a damning report.
It judges that schools, local councils and the Government are all failing adequately to protect children from paedophiles.
Of 58 schools surveyed by Ofsted, the education standards watchdog, hardly any could prove they had carried out checks on teaching staff.
The Government, it added, therefore "has no way of ensuring that recommended vetting procedures have been adhered to" in thousands of schools employing their own staff directly. The Education Secretary, Alan Johnson, is to make an emergency statement in the Commons today ordering all schools to tighten up their procedures.
The report said many councils complained that police vetting procedures for overseas teaching staff were not "robust". It also criticised ministers for failing to insist by law that teacher supply agencies vetted all staff.
The findings provoked outrage from parents' leaders. "I don't think they can get away with it this time," said Margaret Morrissey, spokeswoman for the National Confederation for Parent Teacher Associations. "After last time [when it was revealed that adults with convictions for sex offences were able to continue working as teachers] parents believed they would make it safe. They must now realise you can't just issue guidelines - you've got to have laws.
"OK, there may be thousands of schools around the country where everything is hunky dory but if your child is in the one school where a paedophile has slipped through the net that doesn't matter to you."
Today's report, commissioned bythe former education secretary Ruth Kelly in the wake of the earlier scandal, singled out for special concern checks on staff carried out before the Criminal Records Bureau (CRB) was set up in 2002.
"There is poor practice in recording information about these checks," it added. "This poor practice and the confusion that exists undermine the security of procedures for safeguarding children."
It went on to talk of "major concern" over the vetting of adults who work with children on out-of-school schemes and supply teachers, saying: "Schools surveyed often accept staff from supply agencies on trust and this could compromise the way children are safeguarded."
Only a "small minority" of headteachers knew which of their staff had been vetted. "Once staff are in place hardly any of the schools surveyed take even the simplest of measures in terms of record-keeping: that is to note against the name of each staff member whether they are who they say they are, whether they have the qualifications they say they do, whether they have a criminal record and when these things were last checked and by whom," it added.
"Everybody thinks somebody else is doing this or it is somebody else's job when in fact hardly anybody has secure evidence of when any of the simplest tasks were completed, or indeed that they have been done at all.
"Such practice lacks rigour and thoroughness and makes it appear that the 'world of education' does not take this aspect of the safeguarding of children seriously enough."
The report added there were "unacceptable variations" in policies for vetting governors and volunteers.
Most, however, did insist thatvolunteers who had not been vetted were supervised by someone who had.
Few schools realised it was up to them to demand that supply agencies made checks.
"The exact number of teacher supply agencies is not known," it added. "One official from the Department for Education and Skills estimates the number to be 300 and another estimated it was 1,500," it said.
It said the risk of an agency supplying someone without a check was "low" but added: "It is nevertheless a risk - especially as this survey has revealed that schools rarely ask supply agency staff for proof that CRB checks have been carried out."
Maurice Smith, the chief schools inspector, said: "Schools and local authorities must keep up-to-date and reliable records to prove that the necessary checks on staff have been carried out.
"The repeated recommendations of inquiries into the deaths of vulnerable children urge secure procedures and good record-keeping as the backbone of safeguarding such children."
Mr Johnson has ordered procedures be tightened up, including instructing all schools to ensure they have robust record-keeping procedures - and making it mandatory for CRB and police checks to be conducted on all overseas staff. New government guidelines will spell out the process for checks on volunteer staff.
Under legislation currently going through Parliament employers who fail to institute vetting procedures will face a jail sentence.