Public Service Association (PSA) national secretary Fleur Fitzsimons said the process of renewing the collective agreement was protracted because neither the union or the charity could reach agreement on several issues.
"This dispute is about proper employment practice and human dignity.
"It boils down to a disagreement about [the charity’s] attempts to introduce a 90-day trial period for new employees, which we oppose.
"We oppose 90-day trial periods as they are cruel and unfair, and no human being should be subject to them.
"They leave workers questioning their worth and their future. We expect better from a mental health provider."
She said the employees were low-paid support workers who helped families deal with mental distress and addictions in Dunedin, Oamaru, Invercargill and Central Otago.
The PSA called for facilitation, in relation to the stalled bargaining with the charity over the renewal of its expired collective agreement covering care and support workers.
The collective agreement expired on February 28, 2021.
Both parties accepted the bargaining had been unduly protracted, and recent mediation had failed to resolve their differences.
The charity has set out a summary of the outstanding issues requiring resolution, and has given assurances it remains committed to concluding a collective agreement.
Able Minds chief executive officer Sarah Dowie confirmed the charity had agreed to go to facilitation.
"We are committed to that process and we hope for a productive outcome."
Ms Fitzsimons said the union was also hopeful that facilitation at the Employment Relations Authority would assist the parties in the dispute.
Employment Relations Authority member David Beck said facilitation would be held in Dunedin and dates would be determined "shortly".
