Widespread failings in NHS diabetic care cause 24,000 unnecessary deaths every year, a report has warned.
The National Audit Office (NAO) report found treatment for diabetic patients is a postcode lottery with a massive variation in quality of care from one region to another.
In some regions, only 6% of sufferers received the recommended levels of care compared to 69% in the highest-achieving primary care trusts (PCTs).
Across England only half of people with diabetes received the recommended standards of care in 2009 to 2010.
But not a single PCT delivered the nine basic care processes which reduce the risk of diabetes-related complications such as blindness, amputation or kidney disease.
Barbara Young, chief executive of Diabetes UK , said: "This report shows that diabetes healthcare in England is not meeting the challenge and that much of the colossal amount of money being spent on it is being wasted.
"But by using the money we already spend on diabetes more wisely, we could stop 24,000 people dying unnecessarily every year.
"Action is needed now. Escalating diabetes costs threaten to wreck the NHS budget so this is an issue that affects all of us, not just people with diabetes."
Care Services Minister Paul Burstow said: "There is no excuse for delivering anything but the best diabetes care.
"Nice (National Institute for Health and Clinical Excellence) guidance and Quality Standards set out what good care looks like.
"By exposing poor practice and shining a light on best practice, we are determined to drive up standards for everyone.
"We are already working on a new outcomes strategy covering long-term health conditions and are committed to publishing a companion document on diabetes later this year."
The worst offenders were Mid Essex and Swindon PCTs where less than 9% of patients were given the nine basic tests which are recommended by the Department of Health (DH).
The report's authors said: "The Department holds information to assess performance but there is a lack of accountability for PCTs who fail to ensure that the recommended standards of care are met."
It also claimed the NHS does not "clearly understand" the costs of diabetes at a local level and is therefore finding it difficult to deliver diabetes services in the most effective way.
The report said: "People with diabetes require regular review of clinical indicators of disease progression.
"Without regular monitoring and treatment, this damage can lead to complications such as blindness, amputation and kidney disease."