* Elaborate plans made to idle non-essential staff
* Work critical to national security will continue (Adds intelligence official, Justice Dept spokeswoman)
WASHINGTON, April 6 The CIA, FBI and other U.S. intelligence agencies are planning potentially significant employee furloughs in the event of a federal government shutdown, agency officials said on Wednesday.
Several national security and counterterrorism officials said these agencies had elaborate plans for furloughs if Congress and the White House fail to agree on a budget plan to keep the government funded. [ID:nN05158193]
"The IC (intelligence community) has been looking very carefully at this," one official said.
The key question, the official said, is what do agency managers believe are "essential" intelligence operations.
Intelligence agencies plan to furlough employees deemed engaged in "nonessential" work. The spy units have already made extensive plans outlining which workers are considered essential and which are not.
"Employees whose work is critical to national security will continue to work during a funding lapse," said one senior intelligence official.
Workers assigned to cases examining long-term threats, or broad strategic problems, might face involuntary furloughs, while officials assigned to track down urgent threats would stay on the job.
U.S. congressional leaders said they saw signs of progress for a budget deal in time to prevent a government shutdown after Friday. Negotiators were making progress on a compromise that would avert idling more than 800,000 workers, Republican and Democratic aides said.
The CIA, along with the National Security Agency, will not be exempt from any shutdown.
"The CIA is obviously required to follow the law in the event of a shutdown and would draw down accordingly, and it has conducted exhaustive planning to ensure that it can carry out its mission and continue to protect our nation," another official said.
"No terrorist or nuclear proliferator should think the CIA is going to be off the job."
CIA Director Leon Panetta sent an internal message to agency workers saying: "Regardless of what happens, the CIA will never shut down our responsibility to the nation."
FBI Director Robert Mueller said his agency also is expected to be affected by any shutdown, although essential work would continue.
"We're going to have to look at it day by day. I can tell you that already it's ... adversely affecting morale in the bureau because a number of our persons don't know whether they will be here on Monday, don't know whether they'll get paid and that is tremendously disruptive to somebody who has given their service to some place like the bureau," Mueller said.
But he added: "I do expect that our investigations will continue unhindered."
The Justice Department said that all national security and normal law enforcement functions would continue and that all 116 federal prisons would remain open.
"All criminal litigation will continue without interruption as an activity essential to the safety of human life and the protection of property," said Justice Department spokeswoman Tracy Schmaler.
However, most civil litigation and processing of grants would stop, she said.
The Obama administration has a brief due on Monday in one legal challenge to the president's signature healthcare law, though it likely is in the final drafting stages and would be filed, one department official said. (Reporting by Mark Hosenball and Jeremy Pelofsky; Editing by Xavier Briand)