A new report, published by the association, shows that carers provide about 200 million hours of voluntary care each year - a burden which would cost the government an extra �1.5bn a year if it were paid for.

Stroke services currently cost about �2.3bn a year.

The report says the "hidden help" often causes carers stress and depression while keeping state costs "artificially low".

The Stroke Association says the report shows the need for urgent action to help carers by organising services so that they get the support they need.

"The government cannot continue to rely solely on families to take on the burden of day-to-day care for stroke patients," said Eoin Redahan of the association.

"Far too many people over the age of 65 are, quite unselfishly, looking after their partner. This puts a great strain on their health, both physically and emotionally.

"Something needs to be done, and done quickly, before breaking point is reached."

Third biggest killer in the UK

The report, Stroke Care: Reducing the Burden of Disease, was written by Nick Bosanquet, Professor of Health Policy at Imperial College, London, and Dr Peter Franks of Thames Valley University.

It says extra help could be given to help stroke victims without adding to the NHS budget. For example, improving communication between health and social services could reduce costs as well as involving carers more when patients are discharged from hospital.

In addition, providing specific care for stroke victims in hospital, such as by setting up stroke units, could reduce deaths and disability and may provide a long-term saving.

Stroke is the main cause of disability in the UK and the third biggest killer.

There are currently 300,000 people suffering as a result of a stroke.

'Horrific shame'

The government put stroke on its list of health priorities earlier this year, but has since removed it. Eoin Redahan says this is "a horrific shame". He said it was particularly bad since 90% of people who suffered strokes were over 55 and their partners were often ill-equipped to cope.

"They are relying on their partners' love," he said.