Some 2,300 sex offenders will be among the criminals whose supervision is outsourced to private contractors under government reforms to probation, it was claimed.
Around 3,200 gang members, 8,400 people convicted of domestic violence and 15,900 robbery cases are also among the "medium risk" offenders set for private supervision, the National Association of Probation Officers (Napo) said.
The public will be put at risk if such offenders are taken out of the care of the public sector and transferred to private firms such as G4S and Serco, the union said.
Speaking yesterday, Napo general secretary Harry Fletcher said: "The Government's plans are both chaotic and dangerous."
More top news
Britain's Davis Cup squad has told ITV News more needs to be done to ensure the future success of the country's tennis.
People who write racist comments online have seen their posts blown up on huge billboards near their homes, due to a new campaign in Brazil.
Model Rosie Nelson writes for ITV News, revealing why she is calling for MPs to pass a new law protecting models from becoming too skinny.