The head of Britain's online child protection agency has quit over government plans which would curtail the body's independence.
Jim Gamble, chief executive of the Child Exploitation and Online Protection (Ceop) Centre, offered his resignation over the proposed assimilation of the agency into a new National Crime Agency.
The move is not in the "best interest" of vulnerable children, Ceop said last night. Others went further in criticising the Government's proposals. The shadow Home Secretary, Alan Johnson, said it would "harm child safety networks".
Sara Payne, campaigner and mother of murdered eight-year-old schoolgirl Sarah, said she was "disgusted" by the Government's actions.
But the Home Secretary, Theresa May, defended the plans, stating that the country did not need a "new quango" to carry out child protection work.
Ms May praised the "great job" Mr Gamble had done as chief executive of Ceop and wished him "all the best for the future". She added: "The Government recognises the importance of child protection and wants to build upon the work of Ceop, but does not necessarily feel this is best done by creating a new quango."
Ceop was set up in 2006 tasked with tracking online paedophiles and bringing them to court.
It is currently affiliated to the Serious Organised Crime Agency (Soca).
But under new plans, the agency will become part of a greater National Crime Agency in 2013.
In a statement, Ceop said it was not in "the best interests of children and young people for Ceop to be assimilated into the National Crime Agency, as was announced a short while ago".
It continued: "This direction of travel does not seem to have changed and Ceop's chief executive, Jim Gamble, has therefore offered his resignation to the Home Secretary with a four-month notice period."
Prior to joining the agency, Mr Gamble served as head of Northern Ireland's anti-terrorist unit.
He was one of five senior police figures shortlisted to replace Sir Hugh Orde after he stepped down as the country's chief constable.
As Ceop chief executive Mr Gamble led called for Facebook to set up a "panic button" to give reassurance for young users. The application has been downloaded tens of thousands of times since being launched in July.
In a statement, Sara Payne, Shy Keenan and Fiona Crook – who set up the campaign group The Phoenix Foundation – said: "This is the worst possible news and a devastating blow for UK child protection – Jim Gamble changed the face of child protection for the better, forever.
"We cannot begin to describe how disgusted we are with our own government for betraying him and for betraying all of our children, this cannot be allowed to happen, we must stand up and fight, we must do what is right for the protection of our children against the crimes of paedophiles."
Mr Johnson also praised the work of Mr Gamble, calling him a "passionate advocate for effective measures to protect children from evil individuals".
He added: "The Government's plans will harm child safety networks and their lack of consultation has led to the resignation of Mr Gamble. His expertise will be badly missed."