Ministers are to lose the power to decide if sex offenders can work in schools, the BBC has learned.
Education Secretary Ruth Kelly has faced increasing criticism
An urgent review ordered by Education Secretary Ruth Kelly is understood to have concluded the responsibility should be handed to experts.
Ms Kelly has been under fire following a series of stories about sex offenders being allowed to work in schools.
The Conservatives are calling for an independent inquiry and want to know the scale of the problem.
Ms Kelly has come under increasing pressure since it emerged last week that one of her junior ministers had cleared a PE teacher to work in schools, despite a police caution for downloading child pornography.
Other cases soon came to light including that of a sex offender who had taught at four schools.
The Sunday Telegraph reported Ms Kelly's office sent a letter to William Gibson, 59, allowing him to teach in a Bournemouth school, despite a conviction for indecently assaulting a teenage girl in 1980.
William Gibson was employed in Bournemouth
Conservative leader David Cameron said the situation was "a shambles".
Shadow education secretary David Willetts has written to Ms Kelly demanding she hand over control of the review to an independent figure.
"The Department for Education has still failed to answer the basic question of how many sex offenders ministers have permitted to work in schools since 1997", he said.
The education secretary is expected to give a full statement to the House of Commons in the next few days.
BBC political correspondent John Pienaar said: "Ruth Kelly's statement will explain how the various registers of offenders, and those barred from working with children, will be brought together.
"It's now acknowledged at every level of government that the system of controlling sex offenders' seeking jobs in schools is, in the words of one senior official, 'a mess'."
Gibson was suspended from work at the Portchester boys' school in Bournemouth on Saturday after local authorities became aware of his past.
Keith Mitchell, chairman of the Portchester School Board of Governors, said: "We would like to reassure parents that he won't be returning to the school.
"At no time has there been any question of any impropriety with Mr Gibson while he has been at the school."
He had previously been removed from three schools in the North East and refused work by a supply agency which checked his details with the Criminal Records Bureau.
But his details were never entered on the confidential List 99 maintained by the Department for Education of teachers barred from working in schools.
The Sunday Telegraph said Ms Kelly's office sent a letter to Gibson giving him permission to teach, but warning him about his future conduct.
In the letter, dated 31 January 2005, Ms Kelly's department told Gibson she had decided "not to bar or restrict your employment".
Signed by an official, it says: "The Secretary of State has given weight to the fact that you accept that your actions were unwise and your behaviour was unacceptable; you understand the related consequences of your actions; and, you have undertaken teaching work in recent years to good effect."
Liberal Democrat education spokesman Ed Davey said there was "something seriously wrong" that checks had been carried out yet Gibson was still employed in Bournemouth.
Meanwhile, Margaret Morrissey, spokeswoman for the National Confederation of Parent Teacher Associations said: "There is a feeling [amongst parents] that if the Secretary of State had such little grasp as to what was happening in one of the most important areas of her department it needs to be looked at."
A week ago it emerged PE teacher Paul Reeve had been cleared to work at a Norwich school, even though he had been cautioned for accessing child pornography.
And on Saturday it was reported science teacher Keith Hudson, 52, from Sussex, who was on List 99, was given permission by former Education Secretary Estelle Morris to work in all-girl schools despite a conviction for possessing indecent images of boys.