A three-week spending bill that ended this month’s government shutdown allegedly allows tens of billions of dollars in “black budget” appropriations to be sloshed among secret intelligence agency programs without longstanding congressional notification requirements.

The change is creating unusual allies and consternation among lawmakers who traditionally oversee secretive technology purchases, weapons deals, and covert operations by the intelligence agencies.

The controversial measure amends previous legislation that funded the government by waiving a reporting provision in place since 1947 for intelligence spending.

The waived requirement says: “Appropriated funds available to an intelligence agency may be obligated or expended for an intelligence or intelligence-related activity only if those funds were specifically authorized by the Congress for use for such activities.”

Members of the intelligence committees often are the only people to know details about how secretly appropriated funds are used. Under the waived law, agencies must notify the committees if they reroute spending or spend unallocated funds.

The new wording was requested by the White House Office of Management and Budget at the urging of the Pentagon and was backed by House and Senate appropriations committee leaders over the strident opposition of intelligence committee leadership.

A congressional source working in an office that backed the measure argued it won’t diminish oversight powers, and that the White House was specifically interested in clarifying how recently appropriated missile defense funds can be used.

"There seems to be a misunderstanding about what this provision does," the staffer said, arguing it "does not give the intelligence community a blank check at all" and is intended only to modify a section of law pertaining to missile defense because "without this provision the intelligence community would be unable to spend those funds until passage of an intelligence authorization bill and we do not know when that will be. "

"The intelligence community is required to spend these funds as requested in their budget amendment submission," the staffer continued. "If they want to deviate from that submission, they would have to submit a congressional notification or reprogramming and all four intelligence oversight committees [the House and Senate intelligence and House and Senate appropriations defense subcommittees] and all four committees would have to sign off on those notifications before funds can be spent."

Intelligence committee leaders have a strongly differing interpretation.

“Essentially the intelligence community could expend funds as it sees fit,” Senate Intelligence Committee Chairman Sen. Richard Burr, R-N.C., warned about the change on the Senate floor Monday. “A situation like this is untenable.”

Senate intelligence panel Ranking Member Sen. Mark Warner, D-Va., warned covert operations could be funded without oversight and the House Intelligence Committee’s GOP leadership also opposed the wording.

“This attempted to get slipped in,” Warner said. He support an amendment from Burr to strip the wording, but Senate Appropriations Chairman Thad Cochran, R-Miss., objected to a unanimous consent motion, dooming the effort. Cochran said in a statement he believes the wording “protects the oversight prerogatives” of the intelligence committees and “is consistent with language that has been adopted many times in past continuing resolutions.”

A congressional appropriations aide strongly disagreed with the interpretation of intelligence committee members, saying "this simply allows DOD to use the funds they already have for the purposes outlined explicitly in the budget submission. In practical terms, nothing changes at all."

Steven Aftergood, who directs the government secrecy project at the Federation of American Scientists, has a different view. “The new provision is certainly a departure from the norm that all intelligence activities must be authorized,” he said.

“What is not clear is whether this is simply an artifact of the legislative drafting process, with no particular significance, or whether it is intended as a cover for some unauthorized activity,” Aftergood said. “Normally, I would suspect the former. But the fact that steps to correct the language were deliberately blocked in the Senate … makes you wonder if there is something else going on.”

Aftergood said hypotheticals such as rerouting large amounts of money to arm rebels overseas or to develop surveillance infrastructure are plausible consequences, though he believes “in practice, it would be difficult for an agency to execute some kind of unauthorized activity within the next three weeks that would not leave a discoverable trace.”

“I think the real concern is the precedent that is being set,” Aftergood said. “If this is approved once, as it now has been, it becomes easier to do the same thing again in the future. The message it sends is that intelligence oversight is optional, not essential, and that we can do without it. But we can't.”

Among those concerned is former NSA senior executive Thomas Drake, who was prosecuted unsuccessfully under the Espionage Act after the Baltimore Sun reported on ineffective and expensive post-9/11 NSA programs, including the abandoned $1.2 billion Trailblazer surveillance program, which was chosen over a cheaper, more privacy-protecting alternative.

“Ability to reprogram intelligence funds in secret violates the standing oversight and authorization authority held by permanent select intelligence committees," Drake said. "These very intel committees were formed in the late 1970s as a critical part of reforms instituted after widespread abuse and scandal involving off the books funding of shadow intel ops.”

Drake said the measure "further increases undersight and lack of accountability for the secret side of the U.S. government."

Former NSA technical director William Binney, who worked 30 years at the agency before also criticizing expensive surveillance projects he viewed as infringing on privacy, said he believes that, regardless of the change, “oversight is just so bad it’s just basically nonexistent.”

“NSA management reprogrammed money from my funding lines to other programs all the time,” he said. “From my experience at NSA, those people look at it this way. Once Congress gives money to them, they consider it their money to do with as they see fit. Plus, they do their best to make sure no one can audit their books.”

Current government funding runs out on Feb. 8, setting the stage for another battle over the provision.