A&Es use locums to fill a quarter of senior posts
Almost one in four A&E departments in hospitals in England fill more than 25% of their senior staff vacancies with agency doctors or locums.
The reliance on freelance staff to fill senior posts costs hospital trusts more than £120m a year.
Some trusts have far higher rates of vacancies filled by locums, with three trusts running at rates of more than 50% and the highest at 69%.
The information comes from a Freedom of Information request made by the BBC.
Locum or agency doctors are routinely used to plug gaps in rotas, not just in A&E departments but generally across the health service.
But the BBC has found that many hospitals are routinely using locums to fill the two most senior roles in Emergency Departments; consultants who run the teams and senior registrars.
We approached 142 hospital Trusts in England that run large Emergency Departments, known in the NHS as Type 1 A&Es.
Of those, nearly 90% responded to our request for information about how many of the senior roles were filled with locums, and how much that was costing.
Burden of paperwork
The A&E at North Manchester General is one of the busiest and best performing in the country.
But consultant Dr Jim Butler spends only around 30% of his time caring for patients.
The rest of his day is taken up with paperwork and in particular, finding locums or agency doctors to fill gaps in the rota.
He says it's not an unusual situation.
"I was doing admin all week last week, and in the past I've had periods where I think I went a month without seeing a patient because I had so much admin to do."
Given a shortage of consultant and senior registrar grade doctors working in emergency medicine, Dr Butler says the use of locums is an expensive but unavoidable way of making sure A&E departments are properly staffed.
"Last year I think this department overspent by an enormous sum - a £2m or £2.5m overspend on agency locums.
"We have a lot of vacancies that we're filling so we have no choice."
Locums offer hospitals a flexible way of managing their workforce in response to demand.
When drawn from other specialties or departments they can also help spread best practice and the latest knowledge.
But A&E consultant Prof Suzanne Mason, of the College of Emergency Medicine, the professional body for senior A&E doctors, says there are significant downsides to relying so heavily on locums.
"They often will provide different levels of care and perhaps not such high-quality care as we would come to expect as a specialty.
"That may be due to a lack of knowledge of the local systems but it may also just be due to just a general lack of clinical experience."
But at present hospitals have little choice over their use of locums, according to Bill McMillan from the NHS Employers organisation.
"Tonight at A&E you need to be able to deal with the patients who turn up. You can't say to them, 'You're in the wrong place, we can't do anything for you.'
"So hospitals are obliged to try and fill those rotas as best they can with the best quality people they can. You can hardly blame the patients for turning up.
"You always get a certain amount of flexible workforce in any industry and the health service is no different.
"The question is making sure we recruit locums who are also of the best quality, doing the work we are asking of them, paying the right pay for that. Those are things I think hospitals find really difficult at the moment."
Locum use is not just an issue in England.
Earlier this month, BBC Scotland revealed the NHS north of the border spent a record £82m on locum doctors last year.
A spokesperson for the Department of Health in England said: "A&E doctors are at a record high in the NHS, with 1,187 more than in 2010, including 420 more consultants.
"We've given the NHS £700m this winter to help it respond to the pressure of an ageing population with more doctors, nurses and beds, and plans in every area to manage extra demand."
But Labour says the situation has got worse under the coalition.
Andy Burnham, shadow health secretary, said: "David Cameron has trapped A&Es in a downward spiral and, as doctors leave in their droves, the problems are only getting worse.
"He must urgently get to grips with the A&E crisis, take action to bring down the bill for locum doctors and ensure all hospitals have enough doctors to get safely through the winter."