Avon and Somerset Probation Service is to make budget cuts of around £250,000 in a move that will affect bail hostel staff, according to the union, Unison.
Two hostels in Bristol were subject to scrutiny after a BBC investigation late last year.
Panorama reporters found a convicted paedophile and child-killer living in one hostel who befriended children.
The Probation Service said no budget decisions had yet been made, and it was due to meet unions on Friday.
The Panorama film showed 61-year-old Frank Parker befriending children and speaking of taking a photo of a semi-naked teenager who he had invited to his Brigstocke Road hostel room.
The then Home Secretary, John Reid, ordered an inquiry after the film.
Chris Howe, of Unison, said: "It is alarming that following the highlighting of the issue and the assurances given by the then Home Secretary and the local Chief Probation Officer, the funding problem has been left unaddressed.
"We must now highlight the fact that the hostels now face further cuts in funding which undermine those assurances."
A spokesperson for Avon and Somerset Probation said it was reviewing approved premises, in order to manage budgets and ensure effective delivery of services.
"This process is still under way and decisions have not yet been finalised, he added.
"It is important to stress that this process is taking place in accordance with current board procedures and policies for change management."