The report, due to be published on Tuesday

"What I'm seeing now is a political campaign. Classic Tory diversion tactics. The truth is things have got worse at these 14 NHS hospitals since they got into government."The NHS's medical director will spell out the failings of 14 trusts in England, which between them have been responsible for up to 13,000 "excess deaths" since 2005.Prof Sir Bruce Keogh will describe how each hospital let its patients down badly through poor care, medical errors and failures of management, and will show that the scandal of Stafford Hospital, where up to 1,200 patients died needlessly, was not a one-off.The report will also pile pressure on Labour over its handling of the NHS, with the Conservatives likely to seize on it to attack Andy Burnham, the shadow health secretary who was in charge of the NHS in England from June 2009 until May 2010.

The report, due to be published on Tuesday, will:Name 14 hospitals as having excess rates of death, with hundreds of patients dying needlessly at each of them since 2005;Severely criticise the worst hospital, Basildon and Thurrock University Hospitals NHS Foundation Trust, which had 1,600 more deaths than would have been expected in seven years – a higher death toll than that at Stafford;Show that the warning signs were there for managers and ministers to see, including alarming levels of infections, patients suffering from neglect and appalling blunders such as surgery performed on the wrong parts of bodies.The report was.missioned in February by the Prime Minister after the inquiry by Robert Francis QC into the Stafford scandal exposed appalling lapses in both care of patients and the regulation of hospitals.

Sir Bruce investigated the 14 hospital trusts with the worst mortality rates over the past two years.They were: 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.Research carried out by one of Sir Bruce's advisers, Prof Sir Brian Jarman of Imperial College London, found that in some cases appalling death rates stretched back to 2005.In total Sir Brian calculated that up to 13,000 patients died needlessly in that period. His analysis shows that in the last five years of the last Labour government, from 2005 to 2010, eight of the trusts had death rates well above the average in at least four of those years.