More than 3000 workers who support people with intellectual disabilities will begin voting on possible strike action today.
The vote by IDEA Services support staff will be held at 80 stop-work meetings around the country over the next two weeks."
The E Tū Union said there had already been five months of negotiations between workers and IHC, which operates IDEA Services.
IDEA Services has made no pay offer at all, the union said.
Pressure was also building from staff over constant reviews and roster changes, but IDEA would not agree to job protection, the union said.
It said IDEA was yet to respond to its members' health and safety proposals.
"After five months it's now time for IDEA to invest in its staff," E Tū advocate Alastair Duncan said.
"They've been listening, but they haven't been acting. No one wants to go on strike. No one wants for a minute to think that service users may not be getting fabulous and professional care, but actually we have to say enough is enough."
IDEA Services, which is funded through contracts from the Health and Social Development ministries, said it was unable to make any offers until the government's separate pay equity case with aged care workers was settled.
IDEA chief operating officer Janine Stewart said there had been three negotiation sessions since the union's collective employment agreement expired last October.