The heads of key law enforcement agencies slated to become part of the new Homeland Security Department urged Congress on Tuesday not to split them into pieces, as some lawmakers have suggested.

Officials from the Customs Service, Coast Guard, Secret Service and the just-created Transportation Security Administration told a House Judiciary subcommittee that all of their duties are intertwined and would suffer if not transferred entirely to the new agency.

"The greatest danger to any Coast Guard mission would be to fracture the Coast Guard," said Adm. Thomas Collins, commandant of the service. "The Coast Guard has always met its full set of responsibilities, regardless of department location."

Some members of Congress are concerned that the Coast Guard's nonsecurity duties, such as fisheries management and maritime search and rescue, could become lower priorities under the new department proposed by President Bush. The Coast Guard now is part of the Transportation Department.

"Some fear that the Coast Guard may be put in a position of compromising your other duties," said Rep. Howard Coble, R-N.C.

Questions have also been raised about the Secret Service, which investigates financial crimes such as counterfeiting in addition to protecting officials such as the president and overseeing security at major U.S. events.

The Secret Service director, Brian Stafford, told the panel that both duties "are thoroughly intertwined and interdependent. ... They are the heart and soul of the Secret Service," which is now part of the Treasury Department.

Bush said Monday he was encouraged by congressional action on his goal of moving many of the disparate agencies charged with security issues under one departmental roof.

Congress is moving "with speed and skill and a constructive spirit of bipartisan cooperation," he said at a news conference. Bush contrasted that with congressional delays in approving other White House priorities, including money for defense and anti-terrorism and giving him new trade negotiating authority.

House Speaker Dennis Hastert, R-Ill., has given a dozen committees until Friday to vote on various pieces of legislation forming the new department. The measure is then to be given to House Majority Leader Dick Armey, R-Texas, who is heading a special committee responsible for preparing the bill for House floor debate later this month.

A House Judiciary subcommittee hearing Tuesday is to explore the roles of various security agencies, including the newly created Transportation Security Administration, as part of the Homeland Security Department's mission to stop terrorist attacks within U.S. borders.

John Magaw, chief of the Transportation Security Administration, was to testify along with the heads of the U.S. Customs Service, the Coast Guard and the Secret Service.

The agency would combine 100 scattered federal entities with 170,000 employees and total annual budgets of at least $37 billion.

The Senate also hopes to act on legislation before Congress leaves for its August recess. Both Democrats and Republicans say their goal is to send Bush a final bill by mid-September.

Sen. Joseph Lieberman, D-Conn., the Senate Governmental Affairs Committee chairman who has introduced legislation similar to the Bush plan, has scheduled a July 24 meeting to consider that version.

Lawmakers have suggested ways to reshape the department Bush proposed a month ago.

But it appears unlikely Congress will reverse Bush's decision to exclude the FBI and the CIA from the new agency.

The CIA and FBI have borne the brunt of criticism over the failure of intelligence agencies to anticipate the Sept. 11 attacks, and some lawmakers have questioned the effectiveness of a security agency that does not control CIA and FBI functions.

But one congressional aide, speaking on condition of anonymity, said Monday that the debate has shifted to whether the new agency's Cabinet-level secretary will have enough access to intelligence data, including raw information, to better safeguard the nation against future attacks.