Health Secretary Patricia Hewitt says she will take "personal responsibility" for dragging the NHS out of deficit.
The NHS is currently forecasting a deficit
Ms Hewitt told MPs that the NHS would return to balance by the end of the financial year.
She made the promise during an appearance before the Health Select Committee despite half-year forecasts showing the NHS was facing a deficit.
Figures released last month showed a £94m deficit was being predicted after a small surplus was forecast in June.
During questioning, Liberal Democrat Sandra Gidley asked if the health secretary's job was "on the line" if the NHS did not break even.
Patricia Hewitt replied: "I have said that we will return the NHS as a whole to financial balance by the end of March next year and I take personal responsibility."
However, she pointed out that did not mean every organisation would achieve balance - many hospitals and other health trusts are on course for large deficits, while other parts of the NHS are running up a surplus.
The situation is causing hospitals to close posts, shut wards and delay operations in a bid to balance the books.
The health secretary admitted there would be difficult decisions to be taken on staffing, because "some parts of the NHS in England have taken on too many doctors and nurses".
But she refused to put a number on future compulsory redundancies, beyond the 903 already announced - although critics say 20,000 posts are actually being closed, many through natural wastage.
And Ms Hewitt added it was important to get the NHS house in order over the next few years while it was enjoying record increases in funding - over 7% a year to 2008.
However, critics have raised concerns about how the government is trying to achieve this.
Hospitals and primary care trusts, which are in charge of local services such as GPs and health centres, are facing debts of over £1bn - the same as they racked up last year when the health service's overall deficit was over £500m.
However, reserves are being built up by cutting money earmarked for training and public health as well as taking some of the extra £5.4bn funds due to the NHS this year.
Dr Richard Taylor, a former doctor and independent member of the Health Select Committee, said: "There is concern about the speed we are trying to get back into balance.
"It is being achieved... through cuts to budgets and staff."
And Ms Gidley said: "The only way a secretary of state can take personal responsibility is to step down if they haven't fulfilled their pledges.
"Will she promise to do this at the end of the year if the NHS does not break even?"
Shadow health secretary Andrew Lansley said: "In saying that the NHS financial crisis has been caused by too many staff, Patricia Hewitt has sacrificed the jobs of doctors and nurses to save her own political skin."