Congressional overseers, like everyone else, do not like to seem irrelevant, but President Bush's veto last week of the 1991 Intelligence Authorization Act sent shivers through the august offices of the Senate and House intelligence committees.

It wasn't just that Bush had vetoed their bill. The administration took the position that U.S. intelligence agencies could keep on spending the money allocated to them even without the law that authorized that spending.

The reason, administration officials said, was that intelligence money was also hidden, as usual, in the defense authorization bill.

The implications were obvious, and for the intelligence committees, ominous. The White House was saying they weren't needed.

"That's our concern institutionally," said one staffer. "We don't want to be irrelevant."

Committee lawyers in both houses dug up the statute books. "We have to find a way to protect our prerogatives," a Senate official explained.

They found what they think is their answer in a 1985 amendment to the National Security Act, passed in the midst of suspicion and distrust over unauthorized covert aid to the Nicaraguan contra rebels and, according to a House aide, other instances of the CIA's dipping into reserve or contingency funds to augment authorized programs.

Under the amendment, "appropriated funds available to an intelligence agency may be obligated or expended for an intelligence activity only if those funds were specifically authorized by the Congress for use for such activities."

On the surface, that requirement would appear to have been satisfied by passage of the fiscal year 1991 defense authorization act. The CIA said last Friday night that the Justice Department had been consulted and the agency "will continue to be able to spend appropriated funds."

The intelligence committees disagreed sharply, pointing out that the intelligence authorization bill is the only one that "specifically" authorizes individual activities, with chapter and verse contained each year in a "classified annex."

"We feel very strongly that this bill is necessary for them to carry on their intelligence activities," House intelligence committee Chairman Anthony C. Beilenson (D-Calif.) told a reporter. "The law requires a specific authorization for intelligence activities, which our bill has. In our opinion, it is not included anywhere else."

The reason for that, said one of the committee's staffers, is the defense authorization bill simply aggregates a lot of intelligence programs under line items that don't define the programs. "It's a category that, for reasons of security, covers {up} the real purpose for the funds," he said of the line-item approach.

In the interests of comity, Beilenson and Senate intelligence committee chairman David L. Boren (D-Okla.) are sending Bush a letter asking him, and the intelligence agencies, to adhere to the spending limits in their bill until they can enact a modified version as soon as possible after Congress reconvenes next month.

The White House, it turns out, is preparing to assuage them, even before the letter arrives.

"We are preparing instructions to the intelligence agencies, telling them not to exceed the spending limits in the {1991 intelligence authorization} bill during this interim period," a White House official said yesterday. He pointed out that the president, in his veto message, offered to work out his differences with the intelligence committees in an atmosphere of "mutual trust."

The administration, however, is doing this on its own volition, presumably without giving up its legal contention that the defense authorization bill is an adequate substitute.

Beilenson said the intelligence committees may want to consider next year whether further legislation on that point is needed.

The committees will at least have to address the main reason for Bush's veto. He said he could not accept an Iran-contra antidote in the bill, requiring him to notify Congress when third countries or private citizens are to be used to carry out covert actions. The provision, Bush argued, was too broad because it could be construed to require him to report even preliminary diplomatic contacts or "requests" for help on highly sensitive projects.

"I hope we can resolve the problem with wording that preserves what we want and takes care of the administration's concerns," Beilenson said.