Justice minister Cathy Jamieson is expected to push through plans for a single correctional agency. This will bring together the prison service and councils' criminal justice social work services in one new body.
Although the results of a consultation on the proposals will not be published until next month, the bulk of respondents - including councils, unions and churches - are understood to oppose the plan.
Council leaders have pledged to launch a hard-hitting campaign against the creation of the correctional agency. They claim such a move would fragment offender services, reduce the coherence of existing support for offenders and damage established local networks.
He said COSLA would work with the executive to tackle the problem, but 'centralising and removing a service
from local government' was not the way to reduce 'Scotland's horrendous re-offending rates'.
A Scottish Executive spokesman said that although minds had not been made up, the proposal for an integrated service was a strong one.
'The minister has been clear that the status quo is not an option,' he said.