The government’s overseer of the Troubled Asset Relief Program (TARP) issued a scathing report Wednesday in his regular quarterly assessment of the administration’s bailout efforts.

Special Inspector General Neil Barofsky lashed out at the U.S. Treasury Department for failing to implement clear recommendations from his office that would improve the program and refusing to come forth with critical details of fund usage. Barofsky even went so far as to threaten to subpoena documents from the Treasury and White House.

For an administration that has consistently promised more transparency, the federal watchdog said there’s been little of it when it comes to taxpayers’ $700 billion. Barofsky’s criticism fell squarely on the Treasury’s management of early capital injections and the Department’s resistance to disclose how the nation’s largest banks – the primary bailout beneficiaries – are using the money.

The special inspector general said in the report, “Unfortunately, several decisions by Treasury – including Treasury’s refusal to require TARP recipients to report on their use of TARP funds, its less-than-accurate statements concerning TARP’s first investments in nine large financial institutions, and its initial defense of those inaccurate statements – have served only to damage the government’s credibility and thus the long-term effectiveness of TARP.”

Barofsky’s threat to use the legal system to seize government documents centers on the Public-Private Investment Program (PPIP) in particular. His report says the Treasury is denying access to the records of the affiliates in the program, which Barofsky says are “critical” to identifying conflicts of interest.

Barofsky again voiced concern that taxpayers may never recoup the billions of dollars that have been funneled to the nation’s financial institutions, emphasizing that TARP has driven an even deeper wedge between Main Street and Wall Street.

“It has been widely reported that the American people view TARP with anger, cynicism and distrust. These views are fueled by the lack of transparency in the program,” Barofsky’s report said.

Sen. Chuck Grassley (R-Iowa) has joined other senators to urge the Treasury secretary to let TARP expire at the end of the year. After reviewing the inspector general’s latest report, Grassley said, “It looks like TARP continues to be used as a slush fund for the Treasury Department to pick winners and losers in the private sector. That’s not what Congress agreed to or what taxpayers support.”