Health checks offered to millions of people over 40 are a waste of time and could lead to people taking medicines unnecessarily, the head of the Royal College of GPs has said.
Dr Clare Gerada said the Government was promoting its NHS Health Check programme "against good evidence".
It comes after The Times newspaper published a letter from Danish researchers criticising the programme. They said the health MOTs did not cut the chance of people dying.
Dr Gerada said GPs already do a lot of work to prevent patients developing diseases by carrying out checks such as blood pressure as part of routine GP appointments.
She added: "The (Danish) Cochrane Review shows that there is no benefit in terms of health from the mass screening of those who are well. Nor will it reduce the death rate from diabetes, heart and kidney disease.
"Through mass screening of untargeted populations, we are identifying risk factors, not diseases, and it is inevitable that we will identify people who might have 'abnormalities'.
"These will usually disappear or turn out to be irrelevant, but we run the risk of putting people on unnecessary medication or worrying them unduly.
"At a time when the NHS is having to slash its budgets and GPs and practice nurses are already at breaking point as a result of rising workloads and dwindling resources, this is not the best use of time or money that should be spent on caring for people who are sick or at high risk of illness.
"We should be focusing on what we know and the biggest reductions in cancer and cardiovascular disease have come from major public health campaigns such as the ban on smoking in public places."
But Barbara Young, chief executive of Diabetes UK, backed the programme.
"Far from being useless, there is good evidence that, if properly implemented, it could prevent thousands of cases of Type 2 diabetes a year, as well as having a positive impact for heart disease, kidney disease and stroke," she said.
"And while the £300 million it costs to run might sound like a lot of money, diabetes and other chronic conditions are expensive to treat. This means that once you factor in the savings in healthcare costs, the NHS Health Check is actually expected to save the NHS about £132 million per year."
Dr Paul Cosford, medical director at Public Health England, said: "We know that there is a huge burden of disease associated with conditions such as heart disease, stroke, diabetes and kidney disease and that many of these long term conditions can be avoided through modifications in people's behaviour and lifestyles, and this is what the NHS Health Check programme aims to do.
"Estimates carried out when the programme was introduced by the Department of Health in 2009 showed that NHS Health Checks could prevent 1,600 heart attacks and strokes, at least 650 premature deaths, and over 4,000 new cases of diabetes each year.
"At least 20,000 cases of diabetes or kidney disease could be detected earlier allowing individuals to be better managed and so improve their quality of life."
Dr Cosford said that Public Health England recognised "the programme is not supported by direct randomised controlled trial evidence" but there is an "urgent need to tackle the growing burden of disease which is associated with lifestyle behaviours and choices.
"All elements of the health checks follow well recognised and evidenced clinical pathways approved by the National Institute for Health and Care Excellence (Nice) and the existing relevant evidence, together with operational experience accruing on the ground, is compelling support for the programme."
Health minister Norman Lamb said: "NHS Health Checks have a major part to play in tackling the shocking variation in health outcomes across the country, and in shifting the system from one that deals only with the effects of illness to one that also promotes wellness.
"It is right that the evidence and value for money are kept under review - and early research findings and experience are positive that NHS Health Checks are reaching those most in need and helping to reduce their risk of ill health."