Six patients at Carlisle's Cumberland Infirmary, the first private finance initiative-funded hospital, spent the night on trolleys last week after the trust found itself with no spare beds.

Trust managers said the situation was due to a number of elderly patients waiting to be discharged and insisted that the trolleys used were of such high quality that they were more like beds.

Six patients spent the night in the medical investigations unit on the trolleys, which a spokesperson for Carlisle Hospitals trust said were 2. 5ft wide and designed to accommodate patients for up to 24 hours.

'So far We have had no complaints from the patients who stayed overnight in this unit. Some have indicated that they rather liked the set-up in there. Indeed the use of this unit is part our published emergency strategy. All of the trolleys are new and modern and quite comfortable. '

The leader of Cumbria county council, Stewart Young, has asked North Cumbria health authority to investigate why the infirmary had no spare beds and was also forced to cancel some surgery, a move welcomed.

Trust chief executive Brian Waite blamed the situation on delayed discharge of patients from 40 beds, as well as nursing shortages and an increase in patients needing emergency treatment.

'In some cases - but only a few - we have had to cancel more urgent surgery which, if delayed too long, could have risky consequences as they involve cancer, ' he acknowledged.

Unison regional officer Peter Doyle blamed the bed shortage on having less 'slack in the system' and claimed the size of the hospital was causing problems for both patients and staff.

'The wards are too small and it can be a nightmare for patients because the beds are so close together patients can't sleep. They are constantly shuffling patients around trying to find space for them, ' he said.