The number of operations cancelled at the last minute in English NHS hospitals has increased by more than 4,000, latest figures show.
The cancellations were not for clinical reasons
In the first three months of 2005, 21,566 operations were cancelled at the last minute for non-clinical reasons.
This compares with 17,402 cancellations between October and December and 14,931 between July and September last year.
But government said, overall, more operations were being carried out than previously with no cancellations.
Health Minister Lord Warner said: "Since 2001, the number of last minute cancellations, as a percentage of operations carried out, has fallen.
"This is even against a backdrop of increased activity in the NHS.
"Almost 99% of operations, some 5.5 million, are carried out on time.
"But obviously, one cancellation is one too many and, as capacity increases, the NHS is working hard to ensure all patients are seen on time."
A political row broke out before this year's election when a pensioner, Margaret Dixon, had a shoulder operation repeatedly cancelled due to the lack of a critical care bed for her.
With more and more complex operations being carried out on the NHS, medical experts say there needs to be an increase in the number of critical care beds available in hospitals.
In a bid to reduce cancellations, the government has said it will effectively introduce fines for hospitals that cancel operations and do not offer an alternative date for the surgery.
From later this year, a new date must be given within 28 days of ops being cancelled or they could be given to another hospital with money following.
Liberal Democrat Shadow Health Secretary Steve Webb MP, said the figures were shocking but did not show the full extent of the problem.
"Many people have their operations cancelled the night before they are due to go in for their operation, but these cases are not recorded in the official figures.
"The government should undertake an urgent investigation to find out whether these figures are only the tip of the iceberg."
Conservative Shadow Health Secretary Andrew Lansley said: "It is unacceptable given the amount of money spent in the NHS, that the number of cancelled operations is so high.
"Many operations are cancelled last minute because of Labour's targets: the six month inpatient waiting list target, the overall waiting target, or the four hour A&E target.
"Conservatives would abolish all such targets imposed on hospitals."
Dr Gill Morgan from the NHS Confederation said progress was being made, but added: "Of course it's not just a matter of how operations are managed.
"We will need continued investment in the NHS to ensure we have the capacity to deliver the level of service patients expect."