GPs are warning that the Prime Minister's plans for a more personalised and preventive healthcare system have not been "properly thought through".
Gordon Brown said people will "soon" be offered check-ups for heart disease, stroke, diabetes and kidney disease in a bid to focus attention on prevention.
Details of who is eligible will be announced next month, but the first to benefit will be men over 65 susceptible to abdominal aortic aneurysm.
Mr Brown also said GP surgeries will be able to carry out more diagnostic procedures such as blood tests, heart scans and ultrasounds in a bid to cut waiting times.
But Dr Laurence Buckman, chairman of the British Medical Association's (BMA) GPs' Committee, said: "We would like to be able to say that we fully support this new initiative - focusing on prevention should certainly be congratulated - but as ever the practical considerations have not been properly thought through.
"There has been no attempt to talk to GPs about how these proposals might work.
"Patients will clearly benefit from earlier detection of disease and GPs have been participating in national programmes to screen patients for illnesses such as diabetes and kidney disease for many years.
"However, there is currently a shortage of staff to carry out diagnostic scans, so an expanded screening programme would also require a significant expansion of both personnel and scanning equipment."
"The government proposals are eminently practical. Wish the BMA would say 'thank you' or 'welcome' occasionally to the government, because they only ever moan whenever a new idea is suggested. They obviously don't care all that much about patients" – Name and address supplied