Figures obtained by ITV Border have found that the North Cumbria Health Trust spent 8 million pounds in the past year on temporary doctors.
The so called locums are being relied upon because the troubled trust is struggling to recruit experienced doctors.
The Freedom Of Information request also found that one consultant was being paid £158 an hour.
One local MP has branded the figures 'astonishing'.
The trust says it will cut the number of locums used by 50%.
John Bevir has this exclusive report:
Figures obtained exclusively by ITV Border have found that the North Cumbria Health Trust spent £8 million in the past year on temporary doctors.
The Freedom Of Information request also found that one locum consultant was being paid £158 an hour.
Local MP John Stevenson has branded the figures as 'astonishing', but the trust says that recent recruitment issues are now improving.
The MP for Carlisle believes the drawn out merger process with the Northumbria Trust has created the problems:
Figures obtained exclusively by ITV Border have revealed that the troubled North Cumbria NHS Hospital Trust spent £8 million on locum doctors in the past year.
The Freedom Of Information request found that in the past three years 527 of the temporary medical staff have been employed at the hospitals in Carlisle and Whitehaven.
The highest paid locum consultant was paid £158 an hour.
The figures have been branded as 'astonishing' by West Cumbrian MP Jamie Reed, who is also a Labour shadow health minister.
He believes that unless the problem is dealt with swiftly, "it will make the sustainability of services even harder".
In the past three years, the expenditure on locum doctors has varied wildly, with a significant rise in the past year.
North Cumbria NHS Trust expenditure on locum doctors:
2010 – 2011: £5.8 million
2011 – 2012: £4.95 million.
2012 – 2013: £7.96 million
Although total expenditure on locum doctors has risen, the hourly rates have actually fallen.
Highest hourly rates of pay for locum doctors:
2011 - £158.13 – Consultant Dermatologist.
2012 - £143.75 – Consultant Radiologist.
2013 - £112.95 – Consultant Gastro Medicine.
The trust are expected to comment on the figures later today.