Care home bills for the elderly will almost double to more than £55,000 a year over the next two decades as the number of people requiring help soars, a report has warned.

The study by Saga said average care home bills will jump from just over £28,000 a year - £112,312 over the four years that make up the length of a typical stay in a home for an elderly person – to £56,000 a year - £223,476 for a four-year stay - in 20 years’ time. The figures assume that inflation is 2.5 per cent and care home fees rise by 3.5 per cent a year on top.

Nearly one in five people aged 85 or over are already in long-term care but with people living longer the report warns that growing numbers of families will be hammered by the costs of paying for a care home place.

The burden can be crippling. Anyone who has more than £21,500 of capital has to pay most of the fees themselves. It is estimated that 70,000 properties a year are sold to cover the costs.

The government is looking at a number ways to reform the system, including making personal care free, increasing funding options such as insurance policies and releasing equity from the person's home.

However, some consumer groups fear that, unless it acts quickly, any changes will be too little and too late.

Annie Stevenson at Help the Aged said: “Failure to act now means storing up problems for the future, with more people denied the care they need because of financial constraints. Care home costs have escalated over recent years and look set to reach dangerous new heights.”

Help the Aged wants the government to implement the ideas set down by former banker, Sir Derek Wanless, who published a report on long-term care funding in 2006.

This would involve a certain level of core care services being provided free, while individuals could opt for additional services for which they would pay part of the cost. The government would match each pound up to a set limit. Housing costs would remain means-tested.