The United States Senate resumed debate on homeland security, after lawmakers returned from their August recess. Congress is expected to have a busy legislative schedule before the November elections.

Senator Joe Lieberman, a Connecticut Democrat and chairman of the Government Affairs Committee, opened debate on his bill to create a new cabinet-level homeland security department. "We have crafted here a fundamentally optimistic, and I think realistic, answer to the homeland security challenges we face," he said, "seeing opportunity, not difficulty."

But President George W. Bush has threatened to veto the Senate bill because it does not give him the power he has demanded to hire, fire and transfer workers. The White House maintains the president needs that authority, which is contained in the House-passed version of the bill, to run an efficient operation.

Democrats oppose giving Mr. Bush that authority, as well as a provision supported by the White House that would bar union membership for some employees assigned to the new agency.

But Republicans, including Senator Phil Gramm of Texas, say Democrats are making too much of the proposition. "All this does is give the president the power to set aside elements of collective bargaining when national security is involved," he said. "Interestingly enough, the power the president sought he has under existing law."

Republicans and Democrats believe a compromise can be found for the plan, which would require the largest U.S. government reorganization in a half-century.

Besides homeland security, Congress is expected to consider whether the United States should invade Iraq to topple Saddam Hussein. It a plan being weighed by President Bush, who says the Iraqi leader is stockpiling weapons of mass destruction and poses a threat to international security.

Lawmakers are pressing the White House to consult with them.

In addition, the Congress must complete work on all 13 spending bills needed to keep the federal government running in the new fiscal year, which begins October 1.

The House, which resumes work Wednesday, and the Senate hope to adjourn in early October to campaign for November 5 elections, when control of the Democrat-led Senate and Republican-led House will be in the balance.

On Friday, lawmakers will travel to New York to attend a ceremonial joint meeting of Congress to help mark the first anniversary of the September 11 attacks.