London: Up to 50,000 “excess” deaths were recorded at hospitals during the last Labour government.

As ministers prepare to respond Tuesday to the report into the Mid Staffordshire scandal, figures suggest the number of fatalities was “abnormally high” at 15 further health trusts.

The research - by Sir Brian Jarman of Imperial College, London - covers 2001 to 2010. Half of the hospital trusts he identifies were finally put into special measures this year - prompting accusations that neglect was not tackled despite a series of investigations.

Professor Jarman said: “I warned the Department of Health on multiple occasions about high hospital adjusted death rates; and witnesses have testified under oath there was huge government pressure, because the government hated the idea that a regulator would criticise it.

“In fact, I was so concerned that I wrote to [Labour health secretary] Andy Burnham personally in March 2010 warning him about high death rates at five of the 11 hospitals now in special measures.

“The Department of Health seems to have been, until recently, a denial machine regarding our death rate data.

“It seemed to me as if there was a constant battle with the department producing documents that purported to wish to listen to patients and clinicians but were more spin than reality.

“I felt that there was a culture within the Department of Health which did not want bad news.”

Between all hospital trusts, the professor’s figures show there were 49,500 “excess deaths” - above what could be expected on national survival rates.

This does not mean all these deaths were avoidable but the research illustrates major variations between trusts.

The Francis Inquiry into the scandal at Mid Staffordshire heard hundreds of patients died there from 2005 to 2009 as a culture of neglect, poor management and cost-cutting took hold.

The latest data suggests 16 trusts, including Mid Staffordshire, had “higher than expected” death rates in six or more of the past ten years.

They include Basildon and Thurrock University Hospitals, Burton Hospitals, Medway NHS Trust, George Eliot Hospitals, Tameside Hospitals, North Lincolnshire and Goole Hospitals, East Lancashire Hospital and Colchester - which were all put into special measures this year. Blackpool and Dudley hospitals, which are on the list, were reviewed but not put into special measures.

Labour officials insist the deaths were not all unnecessary, or contributed to by inadequate care.

A party spokesman said Mr Burnham passed Sir Brian’s letter in March 2010 to the regulator, the Care Quality Commission immediately.

He added: “As the expert reports clearly state, these claims are misleading - hospital mortality fell in the last decade. It is regrettable that Brian Jarman is repeating them.”

But Tory MP Steve Barclay said: “It is deeply concerning that Labour ministers gave clearly false reassurance to patients and families that Mid Staffs was an isolated case.

“They now need to come clean and explain whether this was simply for political reasons - to present the NHS in a positive light - or because they had failed to check the clinical evidence available to them.

“The consequence of this failure to intervene is that a further 16 hospitals had abnormally high death rates for the ten years between 2000 and 2010, during which time many patients received poor care which could have been prevented.”

Sarah Wollaston, a Tory MP and practising GP, said: “One of the best ways of moving forward is to make sure the worst performing hospitals are behaving in the same way as the best hospitals, not just in terms of clinicians but also systems such as measures to prevent higher weekend deaths. It’s also about patients’ experience.

“The NHS has to look seriously at variation because otherwise people do die unnecessarily.”

Sir Brian said it was not clear whether or not hospital deaths rates had fallen under the Coalition because some hospitals had changed their coding system to record fatalities.

The Francis inquiry was told many Mid Staffs patients were left lying in their own urine and excrement for days, forced to drink water from vases or given the wrong medication.

It made a total of 290 sweeping recommendations for healthcare regulators, providers and the Government.