The cost of free personal care for Scotland's elderly people has risen by 60% since it was introduced, bringing a renewed warning yesterday that it risks running out of control.

As the numbers who benefit from the scheme passed the 50,000 mark, newly published figures show that the cost rose from £149m to £237m between 2002-03 and 2005-06.

The sharply rising bill will add to the growing resentment in England that Scottish public services are funded from the same Treasury source as the rest of the UK but are more generous than in England.

Free personal care, added to free nursing care, was introduced by the Scottish Executive in July 2002. This was in the face of fierce criticism from Westminster, with warnings that it would become unaffordable as the elderly population grows.

This month, SNP Health Secretary Nicola Sturgeon pledged to "raise the bar", linking payments to inflation from next year and commissioning an independent review to ensure it is "implemented properly and fairly".

A breakdown of the Scottish free personal care figures reveals the greatest increase in cost was for the provision of free care to those who remain in their homes, the figure soaring by 76% from £93m in 2002-03 to £168m by 2005-06.

This is explained by more people aged above 65 applying for the £145 weekly grants to help with personal care, in addition to the £65 fee to support nursing care. It is also due to population change in which older people live longer, and reflects one of the intended outcomes of the policy, in that it helps older people stay in their own homes longer.

The cost of spending on care homes for older people go back to 1999, and show that the total spending on care homes has more than doubled to £478m, while the rise in total spending in supporting elderly people in their own homes rose from £103m to £284m.

The numbers receiving free personal care at home has risen from 27,340 in 2002-03 to 41,240 by last year. Among elderly people given support by social services, the proportion receiving the new payments has gone up from 49% when it was introduced to 72% last year. The number of hours of personal care support rose during the period from 187,200 to 262,200.

The sharpest increases in care home residents and those receiving the payments were in Fife, Edinburgh and Moray.

In England, there has been growing pressure to increase nursing care payments and iron out differences between council areas. Yesterday, English health minister Ivan Lewis sought to dampen political anger. He introduced a uniform fee of £101 for nursing care, admitting the differences had become "a running sore in our healthcare system".

Lord Lipsey, a former Downing Street adviser who argued strongly against adopting Scotland's free personal care policy before it was introduced six years ago, said yesterday that he had been proved right. He went on to say costs will soar five-fold by the middle of the century.