In March the trust, which runs the Royal Cornwall Hospital in Truro, announced that 300 jobs would go.

The trust currently has a debt of almost �16m and it is predicted to grow to �31m.

The Strategic Health Authority has told managers the debt must not grow beyond �20m by the end of this financial year.

'Manage better'

A recovery plan is already in place designed to save about �9m, but this will now have to be extended so that a further �10m can be clawed back.

The trust's director of finance, Ethna McCarthy, said savings would be made by making better use of temporary staff.

Staff have also been told pay overspends will have to be eliminated and steps taken to manage demand for drugs and clinical materials.

Ms McCarthy said: "We are looking at the way we use staff.

"There are a lot of additional hours through locums, agencies and temporary staff.

"Our plan is to remain at the 300 posts that were identified and now we have to manage better the use of flexible hours above the contracted level."