Exeter MP Ben Bradshaw has accused the Government of inflicting "disastrous and expensive upheaval" on the health service as Labour highlighted a worsening financial picture across the NHS.
The opposition claimed the Government has "lost grip" of NHS finances as new analysis of official figures published by Liz Kendall MP, Labour's Shadow Minister for Care and Older People, showed more than one in three acute trusts are currently in deficit for 2013-14 – compared to just one in 10 at the time of the last General Election.
The Royal Devon & Exeter NHS Foundation Trust is among the growing number of health trusts in the region to have plunged into the red, with a £790,000 shortfall for 2013/14.
Seven out of 18 hospital and acute trusts in the region were in deficit, up from three in 2009-10. Plymouth Hospitals NHS Trust, the region's largest hospital, has racked up the biggest deficit of £13 million so far this financial year.
Former health minister Mr Bradshaw said: "If anything, these figures underplay the current deficit crisis facing the NHS in our region. The most recent statements from Trusts show things are even worse.
"Waiting times and lists are growing and services being cut. This is a direct consequence of the Government's disastrous and expensive upheaval of the NHS after they came to power."
The Royal Devon and Exeter NHS Foundation Trust said for each of the last four years cash it receives to treat patients has been reduced by four per cent.
Chief executive Angela Pedder said: "Returning to making a surplus is going to be a considerable challenge if we have to continue making the same level of efficiency savings each year whilst managing increasing demand."
In the Commons, David Cameron dismissed claims the NHS was in financial "crisis", arguing "efficiencies" were being re-invested into frontline services.
A Conservative health spokesman said health bosses have to keep a "tight financial grip as delivering high quality services and balancing the books must go hand in hand", adding: "We won't be taking any lessons from Labour, as deficits in the NHS were a consistent feature of its administration."
Labour said two thirds of hospitals that have gone into the red since the election have done so in the last financial year.
Ms Kendall said: "David Cameron promised that he would protect the NHS. Instead, his disastrous reorganisation has thrown the NHS into chaos.
"Patient care is going backwards as more people are forced to wait longer in A&E, cancelled operations are at their highest for a decade and waits for vital cancer tests and treatments are increasing too.
"We now know that the Government has also lost grip of the NHS's finances. A third of hospitals are reporting deficits, putting patient care at even greater risk in future. The fact that Ministers are having to put more money in to tackle a summer crisis in A&E and the growing backlog of operations shows how desperate the situation now is.
"Forcing through a £3 billion back-room reorganisation when the NHS faces the biggest financial challenge of its life was David Cameron's single biggest mistake on the NHS, and it is patients who are suffering as a result."
