By Nick Martin, Sky News Correspondent
A report into the deaths of as many as 30 mothers and babies from lack of care at a Morecambe Bay trust hospital is expected to be highly critical of NHS managers and health watchdogs.
The investigation, ordered by Health Secretary Jeremy Hunt, has looked into the circumstances surrounding the deaths at Furness General Hospital between 2004 and 2013.
Families of those who have lost loved ones say they have been forced to wait too long for answers. Many are now suing the Trust for negligence.
Carl Hendrickson, whose wife Nittaya and son Chester both died, claims health records showing her heart rate during the birth have gone missing.
He said: "It was terrible. My wife actually died in my arms. I felt her heart stop. I was holding her. So they did an emergency section whilst I was there.
"I knew my wife was going to die once they did that. Chester died shortly afterwards. We have been forced to wait too long for a full explanation."
Six midwives face disciplinary hearings in front of the Nursing and Midwifery Council later this year. But to date no nurses, midwives or doctors have been permanently struck off.
The investigation has heard how midwives failed to alert doctors about patient complications in time because of a 'turf war' between the two professions.
Midwives appeared not to have been on speaking terms with doctors and claimed they were made to feel irrelevant when doctors were called in to help with difficult cases.
The report looked at more than 50 cases where there was serious cause for concern about the treatment given to mothers and babies.
In 2014, a separate investigation accused senior officials at the NHS watchdog the Care Quality Commission of colluding to attempt to delete a report which exposed failures to act on concerns.
The report is expected to lead to demands for reform of the way medical staff are held to account.
It is due to be released to the public at midday on Tuesday.
It follows the public inquiry into the scandal at Stafford hospital where hundreds of patients suffered poor care and neglect between 2005 and 2009.
The King's Fund, an independent health charity, has called for the "archaic" system of midwives investigating complaints made against colleagues to be axed.
Peter Walsh, of Action Against Medical Accidents, told Sky News: "The failures of the regulators of all shapes and sizes singularly and collectively is one of the most disturbing features of this episode and we hope that this report really is able to establish who is responsible for these failings."
