The former head of the Care Quality Commission has said the model of an independent regulator for care in the NHS could not be satisfactory.
Baroness Barbara Young's resignation at England's independent health and social care regulator was announced in 2009.
She was asked about her decision for the public inquiry into Mid Staffordshire NHS Foundation Trust.
The regulator was finding it was quite difficult to ensure doing a good job with its resources, she said.
Further restrictions in resources could be seen "on the horizon", she said, and the resignation was "for a number of reasons".
"It was clear to me that the model of an independent regulator, regulating services provided by a government minister, was never going to be a satisfactory model.
"You'd be a regulator in a very difficult position, with government, accountable to government, but responsible really to the public, with less resource to regulate effectively, and services being more at risk.
"It just felt to me that that was not a job that my skills were best suited for."'Found wanting'
In April 2009, the commission replaced three other organisations - the Healthcare Commission, the Mental Health Act Commission and the Commission for Social Care Inspection.
Lady Young took up the post of chairman in May 2008.
She said: "Inevitably both the Department and ministers were torn.
"[They were torn] between wanting good, strong independent regulation of healthcare and knowing that if good, strong independent regulation of healthcare happened, from time to time they would be put in the dock and found wanting.
"I think that tension worried me not a little. I felt quite able to resist it, but I could see that in resisting it there would be constant conflict and that didn't feel good."
The inquiry is looking into monitoring by regulatory bodies after a higher-than-expected number of deaths occurred at the hospital between 2005 and 2008.