The number of people who are being banned from working with children following sex offences has dropped sharply in the last three years, Labour said last night.
Yvette Cooper, the shadow Home Secretary, raised fears that youngsters were being put at risk and demanded an explanation from the Home Office over the drop.
The fall follows an overhaul of the system of checks on adults who work with children to make it more proportionate.
The reform meant that only people working in sensitive posts or have intensive contact with youngsters and vulnerable adults now have to face police checks.
Freedom of Information answers obtained by Labour showed the number of people barred from working with children as a result of committing sexual offences has fallen from 12,360 in 2011 to 5,758 in 2012 and to 2,800 last year.
And the number stopped working with children as a result of “intelligence sharing” with the police has fallen from 1,542 in 2011 to 471 in 2012 and 351 last year.
Describing the figures as “deeply troubling”, Ms Cooper said: “Parents want to know that if someone has committed serious abuse against children or has a history of grooming or sexual abuse, they will not be allowed to work with children. And schools, sports organisations and other groups need to be able to have confidence in the vetting and barring system.
“Child protection is immensely important and it must not be put at risk because of faulty legislation or failures by the Home Office system.”
A Home Office spokesman said: “It remains the case that anyone committing the most serious offences is still automatically barred from working closely and unsupervised with children.
“The coalition government introduced changes to the barring regime to apply common sense levels, but if someone applies to work with children any serious criminal records or police information are still considered when checks are carried out and, if necessary, they will be barred.”