Jeremy Hunt "misrepresented" a medical study which highlighted increased patient deaths at NHS hospitals at weekends, the editor of a major journal has claimed.
Dr Fiona Godlee, editor in chief of the British Medical Journal, has written to the Health Secretary about her concerns over how he used a September study in the same journal to make the case for his seven-day health service plan.
The study suggested patients admitted to NHS hospitals on weekends were more likely to die than if they were admitted during the week. Mr Hunt called the research a "wake-up call".
But in the letter, Dr Godlee said: "I am writing to register my concern about the way in which you have publicly misrepresented an academic article published in The BMJ."
She asked Mr Hunt, who is embroiled in a row with the journal's owner, the British Medical Association, over contracts for junior doctors and consultants, to clarify his comments.
According to the Independent, the letter went on to say: "Despite the authors' very clear statements to this effects in the paper and elsewhere, you have repeatedly told MPs and the public via media interviews that these deaths are due to poor staffing at weekends, with a particular emphasis on medical staffing.
"This clearly implies that you believe these deaths to be avoidable. I ask you to publicly clarify the statements you have made in relation to this article to show that you fully understand the issues involved."
But health minister Ben Gummer told the paper debating how many of the deaths were avoidable "misses the point".
Writing in the British Medical Journal last month, experts said there was a "clear association" between weekend admissions and worse outcomes for patients.
The study showed that around 11,000 more people died every year within 30 days of admission to hospital on Friday, Saturday, Sunday or Monday compared with other days of the week.
Analysis of hospital records suggested people were 10% more likely to die if admitted on a Sunday compared to a Wednesday, while those admitted on a Saturday had a 7% increased chance of dying.
At the time Mr Hunt, who has warned he is prepared to impose seven-day working on hospital doctors in England, said the research showed the situation may be worse than suspected.
"That's why we urgently need to modernise the contracts for new consultants to make sure NHS patients do not have to worry about a lack of senior clinical presence if they are admitted to hospital on a Saturday or Sunday," he said.