"I would still like it to be resolved but we may have to walk away," Dr Powell said yesterday.
"Our priority is to be able to speak out and raise issues."
In May last year, Dr Powell, who is the group spokeswoman, said she was ending a 13-year membership of ACC community liaison committees.
This was because the group was unhappy about a "gagging clause" linked to a restructured "scheme advisory panel", which limited Acclaim's ability to speak out.
The clause required pre-approval by ACC and MBIE before any panel members discussed in public, including with the news media, any matters before the panel.
She later said the way the panel operated might subsequently be changed, to modify the requirement for ACC and MBIE pre-approval.
Dr Powell said yesterday that, overall, there had been some positive developments at ACC, and Acclaim was receiving far fewer complaints from claimants.
But Acclaim was unsure if the remaining restrictions, including the suggested expanded role of the panel chairman in dealing with all media inquiries, would allow Acclaim to participate with the panel in future.
She would talk to ACC representatives late next week, and hoped the concerns could be resolved.
Throughout her lengthy ACC committee involvement, she had always scrupulously observed "in committee" restrictions, but could later refer to matters discussed in the open section.
Dunedin lawyer Warren Forster said ACC's practice over the panel was "not up to scratch", was too restrictive, and not what the public expected.
Transparency was "the best thing" if ACC wished to restore public trust and confidence, he said.
Asked about Acclaim's situation, ACC spokesman James Funnell said ACC had been discussing with Acclaim "how best they can contribute" to the work of the advisory panel "and the other customer advisory panels (older people, serious injury, sexual violence)".
ACC would continue these discussions as the work programmes of these panels were developed, he said.
