Dangerous criminals released into the community could be housed in new "super hostels", the BBC has learned.
The public often protest against hostels coming to their area
The government wants bigger hostels - it is thought they could have 75 to 100 beds - for people on licence, including those on new Violent Persons Orders.
Probation Boards Association chief executive Martin Wargent said super hostels were "a bad idea".
The National Association of Probation Officers (Napo) said the sites would feel like "mini-jails".
There are currently 100 hostels in England and Wales. Many of these - which house 12 to 25 people - are regarded as unsuitable because of poor security or location.
The Home Office hopes the new hostels can be placed on sites already used by the criminal justice system.
It has emphasised the need to provide secure accommodation for dangerous offenders, but some who work in the approved hostel sector believe the bigger hostels would be less secure and difficult to manage.
Offenders sent to prison for 12 months or more are released at the halfway point on licence, and currently are subject to probationary supervision until they are three-quarters through their original sentence.
Beyond that point they are not supervised but can be returned to prison for the rest of their sentence if they commit another offence.
Last week Home Secretary Charles Clarke, in announcing a shake-up of the probation system, said new restrictive orders on violent criminals would help stop them re-offending.
Judges are to be given more powers to impose conditions on high-risk offenders once they are in the community, under the Home Office plans.
Dangerous offenders could be banned from sports grounds or have limits imposed on how much alcohol they can drink.
Breaching a new violent offender order could carry a maximum of five years in jail.
In extreme cases, the order could last for the rest of the offender's life.
Separate measures would require all prisoners to be seen by a probation officer upon release until their sentences formally came to an end.
The shake-up of probation comes amid concern over recent cases in which criminals on probation committed murders - such as the killings of Reading teenager Mary-Ann Leneghan and banker John Monckton, in London.
Mr Wargent said hostels had operated within the community successfully for decades, partly because they were small-scale, he said.
"Hostels need to be small, they need to be local, they need to be in the communities they serve."
Chief probation officers had been given little more than a week to respond to the Home Office's proposals, Mr Wargent added.
He called on Mr Clarke to "stand back from this one". While his violent offender orders could produce "some modest gain", government action on hostels should be limited to refurbishing the existing stock, he said.
"Mr Clarke needs to talk to the police and local authorities where these hostels are going to be put.
"I think we need to refurbish the hostels we have and see if we can build up capacity, but sticking people in large warehouses is not the solution," he said.
Napo assistant general secretary Harry Fletcher warned the super hostels would be difficult to manage.
"Building super hostels with up to 100 beds would make it more difficult to supervise residents and develop one-to-one relationships.
"In Napo's view, it would be better to expand and improve the existing hostel estate in consultation with key agencies," he added.
Shadow home secretary David Davis said the "fundamental problem" was the lack of adequate prison capacity.
He said the plan appeared to be "yet another ill-thought-out, hasty attempt to generate good headlines for the government [rather] than to actually deal with the actual problem".