Image caption An estimated seven million people are at high risk of Type 2 diabetes in the UK

Three million people in the UK have now been diagnosed with diabetes, says charity Diabetes UK, which warns this new high could create a huge burden on the NHS.

Most of these cases are Type 2 diabetes, caused by the UK's ageing population and rapidly rising numbers of overweight and obese people.

Another 850,000 people are thought to have undiagnosed Type 2 diabetes.

The total represents an increase of 132,000 over the previous year.

In 1996, the number of people diagnosed with both types of diabetes was 1.4 million; the latest figure is three million. Roughly 90% of these have Type 2 diabetes.

It is estimated that, by 2025, five million people will have diabetes.

Experts have previously warned that unless more is done to prevent Type 2 diabetes, and more help is given to those with the condition, the increase could have huge implications for public health.

Diabetes UK said that every year in England and Wales, 24,000 people with diabetes died earlier than expected, a situation that was expected to get even worse without urgent action.

The charity made the announcement of the new figures at the start of a public awareness campaign aiming to reach the estimated seven million people at high risk of diabetes.

TYPES OF DIABETES People with Type 1 diabetes cannot produce insulin. No-one knows exactly what causes it, but it is not to do with being overweight and it is not currently preventable. It usually affects children or young adults, starting suddenly and getting worse quickly. Type 1 diabetes is treated by daily insulin doses, a healthy diet and regular physical activity.

cannot produce insulin. No-one knows exactly what causes it, but it is not to do with being overweight and it is not currently preventable. It usually affects children or young adults, starting suddenly and getting worse quickly. Type 1 diabetes is treated by daily insulin doses, a healthy diet and regular physical activity. People with Type 2 diabetes do not produce enough insulin or the insulin they produce does not work properly (known as insulin resistance). They might get diabetes because of their family history, age and ethnic background. They are also more likely to get Type 2 diabetes if they are overweight. Type 2 diabetes is treated with a healthy diet and increased physical activity. Diabetes UK

Barbara Young, chief executive of Diabetes UK, said she was concerned by the numbers.

"There is no reason to think this will mark the end of what has been a rapid rise in the condition.

"Instead, all the projections suggest that the three million figure will be a grim staging post on the road towards a public health emergency and this unfolding tragedy is already putting huge pressure on the NHS and will have potentially devastating consequences for those people who develop the condition."

But she said this situation was avoidable.

"By identifying those at high risk of developing Type 2 diabetes, we can ensure they start getting support to make the kind of lifestyle changes that can help prevent it.

"And by making sure people who have Type 1 or Type 2 diabetes are already getting the care and support they need, we can help them avoid the devastating complications diabetes can cause."