Patient advocate Lorraine Walsh has resigned from the CervicalCheck steering committee set up to oversee changes in the programme.
Ms Walsh, who was one of the 221 women whose smear tests were read incorrectly and developed cervical cancer, said has she stepped down over yesterday's report.
She said she made the decision to leave because she does not have confidence in yesterday's report.
UK experts found original test results carried out on the slides of 308 women with cancer were wrong. 159 of those also had missed opportunities for diagnosis.
221+ group spokesperson Stephen Teap, whose wife Irene died of cervical cancer, said there are questions that need answering.
Mr Teap said: "We know the HSE had a number of verification steps in place that they weren't satisfied with, they had to return a number of reports that failed the verification process which was concerning itself.
"We raised this issue a number of times a number of weeks back with the Department of Health, so right now we wouldn't be fully standing over this."
