Jeremy Hunt has dismissed top academics pouring doubt on his claim of an NHS 'weekend effect' as getting bogged down in "methodologies".
The Health Secretary made a speech last year claiming 6,000 excess NHS deaths a year happen because care is worse on Friday night through to Monday, but the figure has been torn apart repeatedly.
The claim underpins both the Government's push for a seven-day NHS and trashing out a controversial new contract with junior doctors.
The Secretary of State was today confronted by doctor-turned-MP Philippa Whitford over studies showing "you do not have extra deaths", and that he should "know what the problem is before you spending billions on fixing it".
But the Tory minister swatted away the criticism, arguing that while he was "not an academic" the 'weekend effect' was not going to "get off the hook by disputing the methodologies".
His comments come as researchers from Oxford University argued the claim was a "shambles", and blamed inaccurate data entry.
Prof Peter Rothwell, the lead author of the report and professor of neurology at Oxford University, said there was "very little evidence indeed of a ‘weekend effect’".
“It really is an excellent example of how poor quality data, badly interpreted, can lead to the wrong answer,” he said after examining a report on stroke victims.
Facing a grilling from MPs on Parliament's Health Committee, Hunt said 16 studies backed his belief that hospital care was worse at the weekend - but he did not say that this led to more deaths.
Hunt paraphrased one over-arching analysis which showed "we don't offer the same standard of care at weekends as we offer in the week".
"You could be sick with the same illnesses and the same level of acuity and you would be admitted at a weekday, but not at a weekend," he went on.
"That is what we want to change. We want to be able to promise everyone they will get the same high-quality care every day of the week."
But the SNP MP made clear the original source studies show "exactly the same number of people will have died". "We won't have prevented any deaths, we will just have made our mortality rate look better," she said.
Hunt responded: "I'm not an academic. But I think the mistake would be for a Health Secretary to look at the over-whelming amount of evidence there is of a 'weekend effect' and decide to get off the hook by disputing the methodologies."
But Whitford renewed the point that "you do not have extra deaths". She said: "Is it not beholden on the Secretary of State not to know what the problem is before you spending billions on fixing it?"