The crisis at Wales' largest health board means First Minister Mark Drakeford should sack his health minister, Plaid Cymru has said.
Eluned Morgan has put Betsi Cadwaladr health board in special measures and asked its independent board to quit.
Plaid's Rhun ap Iorwerth said she did not have the authority to carry on.
Welsh Labour said: "This is pretty desperate stuff from Plaid Cymru. The health minister is doing an excellent job."
Mr ap Iorwerth, the Ynys Mon Member of the Senedd, spoke ahead of the second day of Plaid Cymru's spring conference in Llanelli when party members will vote on a new political strategy, enshrining independence as their core purpose and endorsing coalitions, even as a junior partner in government.
Ms Morgan's decision to put Betsi Cadwaladr into special measures - the second time it has forced to come under government supervision - followed a damning audit report.
All 11 independent board members quit after Ms Morgan asked them to stand aside.
They wrote a letter to Mr Drakeford saying they had "no confidence" in the Welsh government's grasp of the situation and questioned the focus on them instead of the executive.
Ms Morgan lacked the powers to make the executive quit but said she read them the "riot act" and wanted further action.
She said it was not her "job to have a grasp on things" and the independent board could not shrug off responsibility.
Plaid, which is in a co-operation agreement with the Welsh Labour government, accused Ms Morgan of humiliating the board.
Mr ap Iorwerth, Plaid's spokesman on health, said: "The people of Wales have lost faith in the health minister. Time and again, she's evaded scrutiny and shifted blame on to others when challenged with the disastrous outcomes of her own policies.
"The patients and staff of Betsi Cadwaladr deserve better from their government. The least they deserve is an apology, but what we all need is the government to step up and take responsibility for this mess.
"If she's not willing to take responsibility now, the first minister should do the right thing on behalf of the people of Wales and remove his health minister."
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