Dementia costs the country £23 billion per year and more than cancer and heart disease combined but receives a fraction of the funding, according to a "wake up call" report out today.

The number of sufferers at 822,000 is also 17% higher than has previously been estimated and will pass the one million mark before 2025, the Alzheimer's Research Trust (ART) said.

Revealing stark differences in research funding, it calculated that for every pound spent on dementia studies, £12 is spent on investigating cancer and £3 on heart disease.

Rebecca Wood, chief executive of the ART, called for greater resources to fight the condition, saying: "The true impact of dementia has been ignored for too long.

"The UK's dementia crisis is worse than we feared. This report shows that dementia is the greatest medical challenge of the 21st century."

She added: "If we spend a more proportionate sum on dementia research, we could unleash the full potential of our scientists in their race for a cure.

"Spending millions now really can save us crippling multi-billion pound care bills later."

According to the report, which was prepared with experts from Oxford University, dementia's overall annual cost dwarfs the £12 billion cost for cancer care and the £8 billion for heart disease.