Staff were balloted on industrial action after pay talks with management broke down, Unison said.
Quarriers’ management offered a 2.5 per cent pay rise and “refused” to target increases at the lowest earners, according to the union.
Unison said it was still considering what industrial action to take so that vulnerable service users were not significantly affected. The first strike is due to take place on 25 April.
Unison regional officer Simon Macfarlane said he hoped Quarriers’ management would “get back round the table and start negotiating seriously”.
He added: “Our members don’t work in social care for financial reward; they do it out of commitment to service users. But we can’t continue to have staff working for Quarriers seeking charity because they themselves are experiencing poverty.”
Quarriers chief executive Phil Robinson said: ”Although overall Quarriers’ local authority contracts income has increased by only 1 per cent on average, the pay increase of 2.5 per cent which Quarriers is offering its staff is exactly the average increase offered across the voluntary sector in Scotland.
“Any strike could put the issue of services under threat, and would appear to show that Unison is unfairly targeting the voluntary sector in comparison with local authority services.”
According to a survey released this week by charities umbrella group Community Care Providers Scotland, more than half of organisations predicted they would have to make redundancies or lose positions next year because of funding shortages.
Kirsten Gooday, policy and development officer at CCPS, said the situation facing Quarriers was “by no means exceptional”. She added: “Many voluntary organisations are going to great lengths to award an uplift of 2.5 per cent despite considerable other financial difficulties.”