The leading nursing union says a chronic shortage of nurses is forcing hospitals to spend millions of pounds hiring agency workers.
The Royal College of Nursing says the Exeter RD&E paid agencies more than six million pounds last year.
The Government claims that nursing numbers have risen by thousands in recent years, but the RCN says its figures are misleading - as they include school nurses and midwives as well as hospital nurses.
And the RD&E says it's seen a year on year increase in the need for nurses, and has invested more than three and a half million pounds over the last two years in increasing its nursing establishment.
The hospital says it only uses agency staff when necessary to maintain patient safety - and keeps agency costs to a minimum.