Jeremy Hunt has blasted the NHS over allegations health bosses failed to investigate the unexpected deaths of more than 1,000 people since 2011 as "totally and utterly unacceptable".
A leaked investigation found a "failure of leadership" at Southern Health NHS Foundation Trust meant the deaths of mental health and learning-disability patients were not properly examined, according to reports.
Responding to an urgent question on the issue in the House of Commons the Health Secretary said: "Firstly, it is totally and utterly unacceptable that, according to the leaked report, only 1% of the unexpected deaths of patients with learning disabilities were investigated."
Mr Hunt said the whole House would be "profoundly shocked" by the allegations.
He said there is an "urgent need" to improve the investigation and learning from the estimated 200 avoidable deaths that happen every week across the system.
He outlined a three point plan to improve things.
"From next June we will publish independently assured, Ofsted-style ratings of the quality of care offered to people with learning disabilities for all 209 CCG areas," he said.
"This will ensure that we shine a spotlight on the variations in care allowing rapid action to be taken when standards fall short.
"Secondly, NHS England have commissioned the University of Bristol to do an independent study into the mortality rates of people with learning disabilities in NHS care and this will be a very important moment to step back and look at the way we look after that particular highly vulnerable group.
"Thirdly, I have committed to the House previously that next year we will publish the number of avoidable deaths by NHS trust."
The leaked draft report, obtained by BBC News, looked at more than 10,000 deaths at the trust between April 2011 and March 2015, of which 1,454 were unexpected.
Shadow health secretary Heidi Alexander said: "These are truly shocking revelations that if proven reveal deep failures at Southern Health NHS Foundation Trust."
The leaked draft report looked at more than 10,000 deaths at the trust between April 2011 and March 2015, of which 1,454 were unexpected.
It found just 195 - 13% - were treated as a serious incident requiring investigation (Siri) and the likelihood of an unexpected death being investigated depended hugely on the type of patient.
The deaths of adults with mental health problems were the most likely to be investigated, with 30% of cases examined.
But the figure fell to just 1% for patients with learning disabilities and 0.3% among over-65s with mental health problems.
Ms Alexander said that if patients with learning disabilities received less attention because they find it harder to communicate it would amount to "the ultimate abrogation of responsibility" and would "shame us all".
She questioned whether services at the Trust were safe as the CQC has found that inadequate staffing levels in community health were impacting on the delivery of social care.
The Labour frontbencher also asked Mr Hunt what he would say to relatives "who will be reliving their grief with a new anxiety".
Mr Alexander said: "The issue raised broader questions about the care of people with learning disabilities or mental health problems.
"Just because some individuals have less ability to communicate concerns about their care must never mean that any less attention is paid to their treatment or their death.
"This would be the ultimate abrogation of responsibility and one which should shame us all.
"The priority now must be to understand how this was allowed to happen and ensure it is put right so it can never ever happen again."
Mr Hunt admitted the Trust's services were not as safe as they should be as the hospitals chief inspector deemed them to "require improvement".
But he said the "hard hitting" report will be published before Christmas and will lead to changes.
The Health Secretary stressed that the culture change required in the NHS remained "unfinished business" from the Mid Staffs scandal.
Mr Hunt said: "The fundamental question that we all need to reflect on is why is it that we don't currently have the right reporting culture in the NHS when it comes to unexpected deaths.
"I think we have to be honest and step back - there are reasons good and bad why this happens, people are extremely busy, there's a huge amount of pressure on the frontline, there's an understandable desire to spend clinical time dealing with the patients who are standing in front of you rather than going over medical notes and trying to understand something that went wrong.
"Sometimes I'm afraid there will be prejudice and discrimination and the whole House will unite in saying that we must stamp that out.
"Sometimes people don't speak out because they are worried that they will get fired or penalised if they do speak out and we do have to move away from a blame culture in the NHS to a culture where doctors and nurses are supported if they speak out, which I'm afraid too often isn't the case."
Health Select Committee chair Sarah Wollaston described the report's findings as "deeply disturbing" and welcomed the measures announced by Mr Hunt, particularly that it will not be treated as an isolated incident.
The Tory MP added: "Can I also ask you, looking at the key findings from the draft report that in nearly two-thirds of investigations there was no family involvement, could you immediately send a message out to all Trusts that, particularly for those who cannot speak for themselves, it is of vital importance to involve family members?"
Mr Hunt said families are too often kept out of decisions and the assumption that things will be more difficult if relatives are involved needs to change.
SNP health spokeswoman Philippa Whitford described the report as "shocking" and "frightening" and said there should be a more systematic approach to deaths, rather than leaving it up to individual Trusts.
She said: "I think it is required that there is a much more systematic looking at the data.
"NHS England publish the annual mortality figures and what's very striking is there are 16 trusts identified with higher than expected mortality that had higher than expected mortality the year before.
"And there does not appear to be any action taken.
"The problem is the benchmark appears to just be average - if you are having poor performance average is set lower, we should be aspiring higher than that."
Tory former cabinet minister Cheryl Gillan said those found to be contributing to patient neglect or failing to investigate avoidable deaths should be held to account by regulatory bodies and also the "full weight of the law".
But Mr Hunt cautioned against "dumping" on NHS staff, adding: "I think if we're going to improve the reporting culture, which is in the end what this report is about ... the fear that many doctors and nurses have that if they are open and transparent about mistakes that they have made or they have seen - that they are going to get dumped on, and that is something that is a real worry for many people."
The Lords heard calls for the introduction of an independent decision-making process regarding investigations into unexpected deaths when Mr Hunt's statement was repeated in the upper house.
Lib Dem Baroness Walmsley called for changes in procedure so that it was not the hospital trust's place to decide which deaths should be investigated.
"In this particular hospital's case, the percentage of unexpected deaths that was investigated is pretty scandalous," she said.
"And, in fact, across the board, only 1% of those with learning disabilities, if they have unexpected deaths, they are investigated."
Health Minister Lord Prior of Brampton said the trust had to be the first line in such cases.