Too many patients with diabetes are developing potentially life-threatening complications because they are not receiving the straightforward care and support they need, according to MPs.
Every year, 24,000 people with diabetes die simply because their disease has not been effectively managed, according to the Public Accounts Committee.
Unless diabetes care in the NHS improves "significantly" patients will continue to die prematurely, the committee found.
In a highly critical report on the management of adult diabetic services in the NHS, MPs also claim that patients face a postcode lottery of treatment.
Fewer than half of patients receive the recommended levels of care, including nine basic care checks which reduce the risk of diabetes-related complications such as blindness, amputation or kidney disease, the report found.
Progress in delivering the recommended standards of care has been "depressingly poor", the authors conclude.
Four fifths of the £3.9 billion spent every year on diabetes services in England is used to treat avoidable complications. And if care does not improve the NHS will continue to incur "ever increasing costs", the committee said.
MPs claim that there is no strong national leadership of diabetes services, no performance incentives for care providers and no accountability arrangements for NHS commissioners.
They added that they have seen no evidence that the new NHS structure will address these concerns.
The committee called on the Department of Health to set out how improvements on diabetes services will be delivered in the reformed NHS.
Margaret Hodge, chair of the committee, said
The NHS spends at least £3.9 billion a year on diabetes services and around 80% of that goes on treating avoidable complications. The number of people with diabetes is set to rise from 3.1 million to 3.8 million between now and 2020 and unless care improves significantly the NHS will face ever-increasing costs.
More than 10 years ago, the Department set out clear minimum standards for diabetes care, including nine basic checks for the early signs of avoidable diabetic complications. Yet fewer than half of people with diabetes are receiving all nine of these tests.
Fewer than one in five people with diabetes have the recommended levels of blood glucose, blood pressure and cholesterol, leaving an unacceptably high number at risk of developing complications, being admitted to hospital and costing the NHS more money.
"The Department gave local NHS organisations freedom to decide how to deliver diabetes services and did not introduce mandatory performance targets as it did for cancer, stroke and heart disease. There is no strong national leadership and no effective accountability arrangements for commissioners.
"Variation in the level of progress across the NHS also means that there is an unacceptable postcode lottery of care, whereby the quality of diabetes care varies dramatically across the NHS.
"We have seen no evidence that the Department of Health will ensure that these issues are addressed effectively in the new NHS structure.
"It must set out how improvements in diabetes care will be delivered under the new arrangements and what steps it will take, alongside Public Health England, to improve public awareness of the risk factors for diabetes such as obesity."
Barbara Young, chief executive of Diabetes UK, added:
Given all the increasingly strong evidence of inadequate care, we simply cannot understand why the NHS has sleepwalked into this situation.
This has led to huge numbers of potentially preventable complications such as amputation and blindness and to many thousands of people dying before their time.
This is a tragedy for those people and their families and the current approach is also a huge waste of public money, as diabetes-related complications are extremely expensive to treat.
It is baffling that the low priority the NHS has given to diabetes has allowed this situation to develop when there is nothing controversial about how to deliver quality healthcare.
A Department of Health spokeswoman said:
We do not accept the conclusion that services are 'depressingly poor' as there has been progress - an extra 750,000 people got all nine diabetes checks over the last four years. But we know there has been unacceptable variation and we are determined to put that right.
By putting GPs and other doctors and nurses at the centre of making local NHS decisions, we will create more integrated care for all patients with long term health problems.
Through Public Health England, local authorities will also be given a ring-fenced budget to tackle problems such as obesity which can then prevent diabetes.
We want to make sure that people living with diabetes are given the care and support they need and we will consider the report's recommendations carefully to help us do this. We will ask the NHS Commissioning Board, in the forthcoming mandate, to make real improvements to how people with long-term conditions are supported and empowered to make decisions about their care.