A “lethal mix” of failings at almost every level led to the unnecessary deaths of one mother and 11 babies in the maternity unit of a Cumbrian hospital, according to an independent report (pdf).

The investigation into deaths at Furness general hospital in Barrow between 2004 and 2013 found maternity services were beset by a culture of denial, collusion and incompetence.

Work inside the unit was found to be “seriously dysfunctional”, with poor levels of clinical competence, extremely poor working relationships and a determination among midwives to pursue normal childbirth “at any cost”.

The midwives at Furness general were so cavalier they became known as “the musketeers”.

In response to the damning findings into what the health secretary, Jeremy Hunt, labelled “a second Mid-Staffs” scandal, both Conservatives and Labour pledged to introduce after the election an independent cadre of medical examiners to check death certificates, which are usually written by junior doctors. These would also hold discussions with bereaved relatives and, where necessary, consult coroners.

The long-promised system was legislated for by Labour in government in 2009 and trialled by the coalition government extensively since. However, funding arguments have contributed to delays to the reforms, which were first demanded in response to the deaths caused by the killer GP Harold Shipman.

Hunt told MPs that the government would also see whether a national investigation team similar to that the experts examining aircraft accidents could establish facts “on a no-blame basis” more quickly than the NHS did at present.

The NHS in England said an already planned review of all maternity services nationally was now expected to report by the end of the year.

Bruce Keogh, the national medical director of the NHS, has been charged by Hunt with investigating whether present codes of practices for health professionals are up to the job.

A plethora of NHS bodies, regulators and the health service ombudsman in England have promised to learn lessons.

The Furness inquiry was set up by Hunt in 2013 to examine concerns over what appeared to be a spate of unnecessary deaths within what became the University Hospitals of Morecambe Bay NHS foundation trust (UHMBT).

A panel of experts investigated events at Furness general from 1 January 2004 to 30 June 2013.

The report’s author, Dr Bill Kirkup, said: “Our findings are stark and catalogue a series of failures at almost every level – from the maternity unit to those responsible for regulating and monitoring the trust. The nature of these problems is serious and shocking.”

Frontline staff were responsible for “inappropriate and unsafe care” and the response to potentially fatal incidents by the trust hierarchy was “grossly deficient, with repeated failure to investigate properly and learn lessons”.

Kirkup said this “lethal mix” of factors had led to 20 instances of significant or major failures of care at Furness general hospital, associated with three maternal deaths and the deaths of 16 babies at or shortly after birth.

“Different clinical care in these cases would have been expected to prevent the outcome in one maternal death and the deaths of 11 babies.

“This was almost four times the frequency of such failures of care at the Royal Lancaster infirmary,” he said, referring to the other main maternity unit run by the UHMBT.

There were a number of missed opportunities, including incidents that were so inadequately investigated that underlying problems went unnoticed.

“We found clear evidence of distortion of the truth in responses to investigation, including particularly the supposed universal lack of knowledge of the significance of hypothermia in a newborn baby.”

Trust managers allowed themselves to be distracted by their pursuit of foundation status, Kirkup said.

“Our conclusion is that these events represent a major failure at almost every level … [There were] repeated failures to be honest and open with patients, relatives and others raising concerns. The trust was not honest and open with external bodies or the public.”

Kirkup said the events had been brought to light “thanks to the efforts of some diligent and courageous families who persistently refused to accept what they were being told”.

He added: “Those families deserve great credit. That it needed their efforts over such a prolonged period reflects little credit on any of the NHS organisations concerned.”

Other trusts must not believe “that it could not happen here”.

James Titcombe, whose son Joshua was among the babies who died, said: “The lack of clinical governance, the fact that these were people protecting themselves, they lost track of mothers and babies, and it’s tragic.

“For me this report really lays out how preventable Joshua’s death was,” said Titcombe.

“I really recognise now that when we talk about missed opportunities we’re talking in my case about not having a six-year-old boy ... To err is human, to cover up is unforgivable.”

Pearse Butler, chair of the trust board, apologising for “some very serious mistakes”, acknowledged the same mistakes were repeated. “And after making those mistakes, there was a lack of openness from the trust in acknowledging to families what had happened. This report vindicates these families.”

The entire composition of the trust board had changed near the end of the period covered by the report. Its hospitals now had 50 more midwives and doctors, while the trust had improved in culture and working as a team.

Hunt, in a Commons statement on the findings, said: “There is no greater pain than for a parent to lose a child – and to do so knowing it was because of mistakes that we now know were covered up makes the agony even worse.

“Within sensible professional boundaries, no one should lose their job for an honest mistake made with the best of intentions. The only cardinal offence is not to report that mistake openly so that the correct lessons can be learned.”

He accepted the investigation’s demand for new guidelines of reporting serious incidents but he added: “I also believe the NHS could benefit from a service similar to the airline accident investigation branch of the Department of Transport.

“Serious medical incidents should continue to be instigated and carried out locally, but where trusts feel they would benefit from an expert independent national team to establish facts rapidly on a no-blame basis they should be able to do so.”

Andy Burnham, the shadow health secretary, pointed out that Kirkup’s investigation said that the long-planned medical examiners might have raised concerns at Morecambe Bay before they eventually became evident.

He recognised Hunt was “committed to them in principle, but will he now agree a cross-party timetable to bring them in without delay?”

Hunt indicated those changes would happen.

Taking up Kirkup’s recommendation for mandatory reporting and investigation as serious incidents of all maternal deaths, stillbirths and unexpected neonatal deaths, Burnham said things could go further.

This, suggested Burnham, should include “looking at how we can move to a mandatory review of case notes for every death in hospital, and also looking at how we can use a standardised system of case-note review to support learning and improvement in every trust”.

Rather than looking at a sample of deaths to measure avoidable harm (as Hunt already intended), this would look “at every single death to learn lessons. It means every single person matters.”

John Woodcock, the Labour MP for Barrow and Furness, said those responsible for the practices laid bare by the report “must be held to account – including re-opening of criminal investigations if necessary.”

Seven individuals are at present being investigated by the Nursing and Midwifery Council in relation to events at Furness hospital, while the General Medical Council said eight individual doctors had been investigated.

One was struck off, one received a warning, and one was given advice. No action was taken against five doctors, while one further doctor was still being investigated.