An NHS trust is facing claims that health bosses covered up a failure to investigate a hospital where mothers and babies died through neglect.
An MP has called for an urgent question to be tabled in the House of Commons following the allegations made against the Care Quality Commission (CQC), who is accused of deliberately suppressing an internal review that highlighted weaknesses in its inspections of University Hospitals of Morecambe Bay NHS Trust, the Daily Telegraph said.
A leaked report due out on Wednesday found that the health watchdog bosses were so concerned about how damning the review would be that they ordered it should never be made public, the newspaper said, and that it should be destroyed.
In accounts of discussions between senior managers about what to do with the findings, one senior manager said: "Are you kidding me? This can never be in a public domain nor subject to FOI (a freedom of information request). Read my lips."
Tim Farron, MP for South Lakes, is so concerned about the allegations he has asked the Speaker of the House of Commons for an urgent question to be tabled.
Mr Farron said: "These allegations are shocking and if true highlight massive failures in the system that is supposed to keep patients safe.
"I am asking for the Secretary of State to come to House of Commons and account for what happened, tell us who is responsible and what he is going to do to hold them to account.
"I have tried to support the families affected by this tragedy for years, but this report shows that collusion could have happened at the highest level - heads must roll for this."
Today's report, by management consultants Grant Thornton, was ordered by David Behan, who became chief executive of the CQC last summer.
It suggests that senior managers at the CQC were more concerned about protecting the organisation's reputation than about patient care when they ordered the review to be suppressed, the Telegraph said.
Concerns about the maternity unit at Furness General Hospital in Cumbria came to light in 2008, but the CQC gave the Morecambe Bay trust the all-clear in 2010.
But when a review into maternity care was ordered the following year it was so damning it was suppressed, the newspaper said.
An official who carried out the review was asked to delete it and write a different review without criticism of the CQC.
Today's report said he felt he was "being put in a very difficult position" and was asked to do something that was "clearly wrong".
The report says the man "said that he felt very uncomfortable about the apparent weight that was being given in the meeting to the potential media impact and reputation damage his report findings might cause CQC. His view was that the focus instead should have been on patient safety and the protection of service users".
University Hospitals of Morecambe Bay NHS Trust was warned in 2011 that it would be closed down without major changes.
Last night a spokesman for the CQC said the organisation's culture was changing, saying: "We let people down, and we apologise for that.
"This report reveals just how poor the CQC oversight of University Hospitals Morecambe Bay was in 2010.
"This is not the way things should have happened. It is not the way things will happen in the future. We will use the report to inform the changes we are making to improve the way we work and the way we are run.
"There is no evidence of a systematic cover-up or of any collusion between CQC and the Public Health Service Ombudsman, but the example of how an internal report was dealt with is evidence of a failure of leadership within CQC and a dysfunctional relationship between the executive and the board.
"There is evidence of a defensive, reactive and insular culture that resulted in behaviour that should never have happened."
David Prior, CQC's chairman, said: "CQC's chief executive, David Behan, was absolutely right to commission an independent report into CQC's handling of the registration and subsequent monitoring of UHMB - and absolutely right to publish it in full.
"The publication draws a line in the sand for us. What happened in the past was wholly unacceptable. The report confirms our view that at a senior level the organisation was dysfunctional. The board and the senior executive team have been radically changed."