Activists will picket IHC's headquarters to protest the organisation's interest in the Government's state housing sell-off.
The intellectual disability support service revealed in August that was considering purchasing some or all of the 1140 state houses the government intends to sell in Tauranga.
State Housing Action Network says it's "appalled" at the move, with its supporters staging a protest outside the IHC's Wellington office today.
The network's convenor John Minto accused IHC of "colluding in the betrayal of the most vulnerable families", and allowing the government to walk away from its responsibility.
"We want the public to know that this once proud organisation, IHC, has become an eager collaborator in one of the National government's most despicable policies," Mr Minto said.
"IHC would not support Victorian-era approaches and attitudes to people with disabilities so neither should they support the National government returning housing for low-income families to Victorian times when the only options were charities and churches."
IHC national communications manager Gina Rogers said she wasn't authorised to respond to the network's criticism.
However, she indicated the organisation was still in talks with the government about the Tauranga state housing transfer.
"We're still interested in the process, and we need to look very carefully at whether it will work for us," Ms Rogers said.
"Obviously we're pretty focused on making sure that whatever deal we did or didn't do meant really good outcomes for the people that we're supporting."
Expressions of interest in the Tauranga transfer and a second sell-off of 370 Housing New Zealand homes in Invercargill, close in early 2016.