Bed-blocking is being driven up because hospitals are discharging patients earlier and social services do not have the resources to cope, the Association of Directors of Adult Social Services has claimed.

Figures released to the Liberal Democrats last week revealed the numbers of bed days lost through delayed discharges increased by 30 per cent from 2005-06 to 2006-07.

The Department of Health figures showed just over 1 million bed days were lost in 2006-07 through 'delayed transfers of care' involving elderly patients. In 2005-06 it was 776,000 days, with almost half of NHS trusts reporting increased delays the next year.

The Liberal Democrats blamed funding shortfalls and a lack of co-ordination between health and social care organisations. They said the most common reason cited for a delay was problems in waiting for arrangements or assessments for council-funded social care.

But Association of Directors of Adult Social Services president Anne Williams said the rise was being driven by hospitals designating patients 'fit to discharge' earlier than previously.

'People are being discharged far sooner than they used to be. Much more of the rehab and recovery for post-operative patients is happening at home now,' she said.

'People should only be in hospital for the minimum time, but the funding streams need to reflect where the care is now happening, and social care hasn't seen anything like the huge amount of extra resources the NHS has had.'

Ms Williams added that the huge increase in the rate of emergency readmissions - which rose 31 per cent for over-75-year-olds from 1998-99 to 2005-06 - indicated that at least some of the discharges were clinically inappropriate.

Liberal Democrat health spokesman Norman Lamb said delayed discharge was 'bad for patients and bad for the NHS'. He added that it could undermine infection control because patients could not be isolated if beds were short.

'It puts staff under undue pressure and risks corners being cut in order to get new arrivals admitted on time,' he said.

Concern over the problem in England follows a report from the Wales Audit Office which said delayed discharge was costing the Welsh NHS£69m a year and 'compromised' patient care.

While the number of people whose discharges were delayed had decreased over the two years to 2006-07, the number of bed days lost had increased, indicating that a few people were being delayed for much longer.