Surgeons at hospitals in England are being left "kicking their heels" because operations are being cancelled due to bed shortages, NHS leaders say.
Royal College of Surgeons president Clare Marx said the "shocking waste" was a symptom of NHS underfunding.
In a joint letter to the Sunday Times with NHS Providers chief executive Chris Hopson, she said patients and staff deserved better.
NHS England said only 1% of operations were cancelled at the last minute.
The letter said: "Because of bed shortages, staff including surgeons are now sometimes left kicking their heels, waiting for beds to become available so they can operate.
"Too often managers, nurses and doctors waste time trying to find somewhere to look after patients [after surgery].
"At a time when the NHS is being told to make the most of its resources, this is a shocking waste."
To minimise the risk of infections and delays in getting treatment, hospitals are meant to have no more than 85% of beds occupied.
NHS Health Check
A week of coverage by BBC News examining the state of the NHS across the UK as it comes under intense pressure during its busiest time of the year.
Read more on our special report page.
But Ms Marx and Mr Hopson, whose organisation represents NHS Trusts, said that overnight inpatient beds were "routinely" 89% occupied.
"This is partly because there is not enough social care capacity to look after our frail older patients in the community, so increasingly they cannot be discharged from hospital," they said.
The latest figures from NHS England revealed that more than 95% of beds were occupied last week.
Surgeon George Reese told the BBC Two documentary Hospital he recently had to delay operating for several hours until he could establish whether a bed would be available for one of his patients.
"Why should I feel victorious that I'm actually just allowed to do what I should have started doing at eight o'clock this morning?" he said.
"It's because the beds are so bad at the moment that it seems rare to be able to be allowed to actually go ahead and do an operation. Very bizarre."
And brain surgeon Kevin O'Neill told the documentary: "We are pretty much at 100% capacity - beyond actually.
"Ideally, what you need is a bit of leeway to deal with the reaction of surges in demand and emergency care...
"That's why we spend a lot of our time, rather than operating, running round trying to sort things out."
Health Secretary Jeremy Hunt has previously said performance in elements of the NHS in England was "completely unacceptable".
His comments came as record numbers of patients spent more than four hours in accident and emergency units in England in January, according to figures leaked to the BBC.
Figures showed that 82% of patients in A&E - rather than the target 95% - were transferred, admitted or discharged within four hours during January.
The number of operations cancelled by the NHS in England also hit a 15-year high last year.
A total of 82,730 planned operations were cancelled at the last minute for non-clinical reasons - a third higher than in 2010.