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
Barbara Young, chief executive of Diabetes UK, added:
A Department of Health spokeswoman said: