Warning that putting tasks such as supervising offenders in community up for competition could see service disappear

Probation officials have warned that the increased role for the private sector in providing community penalties could lead to fragmentation of the probation service and offenders "falling through the net".

Heather Munro, the London probation trust chief executive, raised her concerns after chief officers of probation were asked to examine the "potential for core probation services" to be put up for competition.

It is not thought that entire probation areas will be turned over to the private or voluntary sector but it is likely that chunks of key probation work, such as supervising offenders in the community and prisoners on release and writing pre-sentence reports for the courts, could be taken out of the public sector.

So far the unpaid work programme in London ? formerly community service and now known as community payback ? and the management of bail hostels have been put up for competition. Ministers are also preparing to put ?1bn worth of contracts for the electronic monitoring of criminals out to tender when the current eight-year contract comes to an end next March.

Munro, vice-chairwoman of the Probation Chiefs' Association, said increased private sector competition sector could lead to a fragmentation of the system and the role of probation disappearing.

"A real concern is the fragmentation, because we know that that's when things go wrong," she said. "If you've got one set of people delivering people on community payback, somebody else delivering tagging services, somebody else trying to hold the whole thing together ? there is a real worry about fragmentation and that's when people fall through the system," said Munro.

"We know there's enough fragmentation now between youth and adult, between the different criminal justice agencies. How will the police and others in criminal justice know who to talk to about a particular local offender? At the minute, they come to us if they're on a community order. If there's a lot of organisations involved, is it going to be as easy?"

Probation chiefs also fear that the national offender management service, which runs prison and probation services, was looking to transfer risk from the public to the private sector.

Munro said her concern was that the role of probation could disappear as more of the service is put out to competition.

She also argued for the management of court orders and the writing of pre-sentence reports to stay in the public sector. "I can't believe those sort of things are best managed in a private sector setting," Munro added.

Her remarks come as figures show that 76% of offenders on community punishments complied with the terms of their community order or release licence despite a Ministry of Justice target of 72%. They also show 67,000 out of 89,000 community payback orders were successfully completed.