David Rosenberg from Gluskin Sheff said lending has fallen by over $100bn (£63.8bn) since January, plummeting at an annual rate of 16pc. "Since the credit crisis began, $740bn of bank credit has evaporated. This is a record 10pc decline," he said.
Mr Rosenberg said it is tempting fate for the Fed to turn off the monetary spigot in such circumstances. "The shrinking in banking sector balance sheets renders any talk of an exit strategy premature," he said.
The M3 broad money supply – watched by monetarists as a leading indicator of trouble a year ahead – has been contracting at a rate of 5.6pc over the last three months. This signals future deflation. The Fed's "Monetary Multplier" has dropped to a record low of 0.81, evidence that the banking system is still broken.
Tim Congdon from International Monetary Research said demands for higher capital ratios and continued losses from the credit crisis are both causing banks to cut lending. The risk of a double-dip recession – or worse – is growing by the day.
"It is absurdly premature to think of withdrawing stimulus while bank credit is still sliding. To have allowed this monetary collapse to occur a full 18 months after the financial cataclysm is extreme incompetence. They seem to have forgotten that the lesson of the 1930s was the falling quantity of money," he said.
Paul Ashworth, US economist for Capital Economics, said that certain Fed officials are clearly worried about lending since they slipped in a warning that bank credit "continues to contract" in their latest statement.