MPs have criticised government plans to introduce GP-led health centres in every part of the country, citing a lack of transparency in the decision-making process.
The Commons Health Select Committee said officials have been unable to give details of the criteria on which primary care trusts (PCTs) should decide if they need the new "polyclinics".
Ministers said every one of England's 152 PCTs must open a seven-day-a-week health centre, open from 8 am to 8 pm. The GP-led centres aim to bring together a wide range of services, such as diagnostic testing, minor surgery, blood tests and X-rays.
But while some places in England may benefit from the clinics, there is not enough evidence to say all areas require them, the committee said.
The report, which examined Lord Darzi's NHS Next Stage Review, said: "While some PCTs, particularly those which are 'under-doctored' or with a high burden of disease, would undoubtedly benefit from more primary care services, it is less clear how other PCTs would benefit.
"We are not convinced by the Department of Health's argument that all PCTs should have a GP-led health centre.
"In particular, PCTs lack analytical and planning skills and the quality of their management is very variable."
British Medical Association (BMA) chairman Dr Hamish Meldrum said the findings were in line with the BMA's view that the plan was "short-sighted".