An independent health watchdog has come under fire over failings in the way it handled deaths at a maternity unit in Barrow.
A scathing report by MPs has concluded the Care Quality Commission (CQC) has not earned public confidence.
Failures in the registration process and the handling of a whistle-blowing board member have "further undermined" public assurance in the regulator, the Health Select Committee said.
And despite "sustained criticism" the organisation has failed to define its core purpose, it added.
The body, which inspects hospitals and care homes to ensure standards are being met, was created in 2009.
But MPs today said the CQC has not yet managed to generate public confidence.
The CQC's registration process "was not effective in ensuring that all essential standards were being met" at University Hospitals Morecambe Bay NHS Foundation Trust, the report states.
The maternity unit at one of the trust's hospitals - Furness General Hospital in Barrow, Cumbria - is at the centre of a police investigation concerning a number of deaths.
"It is failures such as those witnessed at Morecambe Bay which undermine public confidence in the CQC's essential standards," the report states.
Public confidence in the organisation was also weakened last year when the body failed to address issues raised by board member Kay Sheldon, MPs added.
They said that it was "regrettable" that Ms Sheldon was forced to voice concerns about poor leadership and safety breaches at the regulator at the public inquiry into failings at Mid Staffordshire NHS Foundation Trust.
The report states: "The decision by CQC board member Kay Sheldon to give evidence as a whistle-blower to the Mid Staffs Public Inquiry added to the controversy surrounding the CQC.
"She identified serious failings within the management, organisation, functions and culture of the CQC.
"Kay Sheldon's concerns were legitimate and it is unacceptable that the CQC failed to address and act on them before she felt compelled to approach the public inquiry."
The outgoing chair of the CQC was grilled about her handling of Ms Sheldon when she appeared before MPs in September last year.
Reports suggest that Dame Jo Williams, who is soon to be replaced by Norfolk and Norwich University Hospitals NHS Foundation Trust chairman David Prior, asked then-health secretary Andrew Lansley to remove Ms Sheldon from the board on the day that she gave evidence to the inquiry.
Dame Jo told the committee that she was "surprised" to learn that her colleague decided to speak at the inquiry, adding that it led to a breakdown of trust between the pair.
The report concluded that Mr Prior should overhaul the governance structure at the organisation when he starts his role later this month.
"Board procedures should provide for regular assessments of its own effectiveness and they should also provide a clear process by which a board member can express concerns about the performance of the chair," the report states.
Conservative Stephen Dorrell, chair of the committee, said: "The CQC's primary focus should be to ensure that the public has confidence that its inspections provide an assurance of acceptable standards in care and patient safety. We do not believe that the CQC has yet succeeded in this objective."
He continued: "Public confidence in the CQC was further undermined last year by its failure to address issues identified within its own management, organisation, functions and culture by its own board member Kay Sheldon.
"It is regrettable that she felt compelled to approach the Mid Staffs Public Inquiry to secure a hearing for her concerns.
"It is essential that the CQC reforms its culture and working practices to address these shortcomings.
"The new CQC Chair must, as a matter of urgency, overhaul its governance structures to ensure the board sets clear objectives for the organisation, holds the executive effectively to account against these objectives, and regularly assesses its own performance and effectiveness."
The report also questions whether the body should take the lead on patient safety in hospitals and care homes.
"We agree that the CQC's fundamental purpose is to ensure that health and social care providers meet those essential standards which ensure patient safety," it states.
"The committee remains concerned that the role and duties of the CQC are not sufficiently clear.
"Responsibility for patient safety lies at the root of high quality patient care, but is in danger of being obscured by other competing priorities... we recommend that the Secretary of State should reconsider whether prime responsibility for patient safety should reside with the CQC."
The report goes on to say that the CQC must be "more diligent" in communicating the outcomes of inspections - especially to residents in social care homes.
Mr Dorrell said: "The CQC also needs to be more diligent about communicating the prompt, accurate and complete outcomes of its inspections directly to operators, residents and relatives, as well as to public sector commissioners.
"No one who relies upon a service should be expected to scour the CQC website for inspection results, or chance upon them in a local newspaper report."