Thousands of hospital patients are dying unnecessarily every year from blood clots which could be prevented, a committee of MPs warned today.

Blood clots kill more than 25,000 patients in England - more than breast cancer, Aids and traffic accidents combined - yet doctors will not get official guidelines to prevent them for three years, said the Commons health select committee.

The committee also warned the guidance by the government's drugs and treatment watchdog was likely to be too narrow in scope to tackle the scale of the problem, which kills more than 25 times more people per year than the MRSA hospital superbug.

The National Institute for Clinical Excellence (Nice) is set to issue guidelines on preventing blood clots by May 2007, but this was attacked as "tardy" by the committee. The MPs were also critical that the guidance will only cover a limited number of patients who have had surgery.

The committee's chairman, Labour MP David Hinchliffe, said they will be "too late, too narrow in scope and will not go far enough to prevent more unnecessary deaths". The committee called for all hospital patients to be assessed and given preventative treatment against clots.

Mr Hinchliffe expressed concern that despite the "alarmingly high" number of deaths from blood clots most medical staff were "simply not aware of the extent" of the problem.

"Considering the sheer numbers of people who die from the condition I find it shocking that this have been allowed to go unchecked for so long," the MP said.

The report examined what measures hospitals took to prevent patients getting dangerous blood clots. These include clots in the leg veins, called deep vein thrombosis (DVT), which can break off and lodge in the lung. This condition is called pulmonary embolism and is fatal in 30% of cases without treatment. But many of these deaths could be prevented with blood-thinning drugs, stretching exercises and compression stockings.

Mr Hinchliffe said: "Doctors need a comprehensive set of guidelines that will cover all patients to allow them to tackle the problem head on. We know that there are drugs available that dramatically cut the chances of patients developing a blood clot.

"They are cheap, effective and easy to administer and should be used to much greater effect. We recommend that each hospital creates a thrombosis team as soon as possible, charged with the responsibility of reducing the risk that patients face."