Serious concerns were raised last week about the quality of SEND support in Bury, with inspectors warning that progress has been hampered because of complacent leadership.
Inspectors from Ofsted and the Care Quality Commission said children and young people with SEND had been "let down" by provision, adding that leadership in the area had been "delusional" about the quality of services.
The National Deaf Children's Society previously wrote to Bury Council in March, raising concerns about the potential impact of proposed cuts to sensory services.
Jess Reeves, campaigns manager at the National Deaf Children's Society, said: "This is by far the most damning report into SEND services that I have ever read. Families across Bury will be appalled to hear how badly they are being let down.
"It's clear from this report that deaf children in Bury need more support, not less - and yet the council is planning huge cuts to what remains of local SEND services.
"This includes the specialist education support service which deaf children, young people and their families rely on.
"My question to council leaders is very simple: how can you justify these cuts, when you are already failing some of the most vulnerable children in Bury?"
However, Bury Council strongly refuted NDCS's claims about the extent of cuts to services for deaf children. It said one post from the sensory impairment team had been deleted saving £29,000 from an overall budget of £928,000, but this had been vacant since 2015 and had not impacted on services.
Two other teaching posts for deaf children are also vacant.
A Bury Council spokesman said: "An ongoing service review will determine what will happen to these posts - this will be carried out in consultation with children and their families, and no decisions have yet been made.
"Bury, in common with councils across the country, has cut and is continuing to cut its budget due to government reductions in our funding: in Bury's case, to the tune of around £100m over a decade.
"We will continue to review all council services to ensure we make the best use of our decreasing budgets to support our most vulnerable children and adults."