Hospitals are braced for tough criticism over thousands of needless deaths in a key report next week.
NHS medical director Prof Sir Bruce Keogh is set to detail failings at 14 trusts in England thought to have had "excess" death rates going back years.
He is expected to describe poor care, medical errors and management blunders, suggesting that the Stafford hospital scandal was not a one-off.
Tories are likely to seize on the findings - due to be published on Tuesday - to attack Labour's handling of the health service.
Shadow health secretary Andy Burnham was in charge of the NHS between June 2009 and May 2010.
David Cameron commissioned the report in February after Robert Francis QC's inquiry into the Stafford scandal exposed appalling lapses in both care of patients and the regulation of hospitals.
Sir Bruce has been examining 14 hospital trusts that have been outliers on mortality indexes over the last two years.
They are: Basildon and Thurrock in Essex; United Lincolnshire; Blackpool; The Dudley Group, West Midlands; George Eliot, Warwickshire; Northern Lincolnshire and Goole; Tameside, Greater Manchester; Sherwood Forest, Nottinghamshire; Colchester, Essex; Medway, Kent; Burton, Staffordshire; North Cumbria; East Lancashire; and Buckinghamshire Healthcare.
A Department of Health spokeswoman said: "We are not prepared to speculate about the contents of Sir Bruce's review, or our response to it. We've shown consistently that we expect the NHS to be accountable where things go wrong.
"That is why the Prime Minister ordered an investigation to get to the bottom of these issues."