The competition among Virginia, Maryland and the District over the headquarters for a federal Department of Homeland Security is escalating as regional leaders wage an increasingly public squabble for the project, a potential economic bonanza.

The D.C. mayor and Virginia's junior senator fired off dueling letters to President Bush and Homeland Security director Tom Ridge this week, amid a flurry of behind-the-scenes meetings and calls among congressional staff members, state economic development officials and federal agency representatives.

Mayor Anthony A. Williams (D) appeared yesterday with Del. Eleanor Holmes Norton (D-D.C.), who has pressed him to use his position as a co-chairman to the White House's Homeland Security Advisory Council to promote the District's candidacy.

"I am here to sound the alarm," Norton said. "We believe the administration is not fully aware of the blow to the city's economic gut this job loss would entail. . . . If the administration pulls thousands of jobs out of the nation's capital, it will wreak havoc."

Williams said Congress and past presidents have made it federal policy to house key government agencies in the capital. "It would send the wrong message to not have the Department of Homeland Security in the capital," Williams said, calling the department's location "the highest priority."

The District's case was supported by the National Capital Planning Commission. Citing legal precedent, the commission's policies and the impact on federal employees, John V. Cogbill III, chairman of the government planning agency, wrote Ridge on Monday that a site in the District "will demonstrate to Americans at home and to the world at large the country's fearless resolve to conduct the war on terrorism."

On Tuesday, Sen. George Allen (R-Va.) announced that he had sent his own letters to Bush and Ridge, saying that "Virginia is ready to serve" as the department's host.

"Virginia is already home to the Pentagon, the headquarters of the Central Intelligence Agency and numerous other programs and installations involved in protecting the safety and freedom of Americans," Allen wrote. "Within a short distance to the White House and Capitol, Virginia offers numerous locations" suitable for the short and long term.

Maryland's House delegation, led by incoming Minority Whip Rep. Steny H. Hoyer (D), has also appealed to administration officials, and Sen. Barbara A. Mikulski (D) wrote Ridge last week. She touted military installations such as Fort Detrick and the state's advantages in offering "established secure federal facilities, continuity of operations in the event of an attack and a large pool of educated workers."

The competition is especially intense because of tight deadlines. The administration has until Jan. 24 to announce the organization and location of the department, which is to consolidate 22 agencies and 177,000 workers. The government estimates that 10 percent, or 18,000 jobs, are in the Washington area.

The General Services Administration has asked interested developers for 225,000 to 275,000 square feet of leased space initially. Some federal officials believe the department will grow over time to fill its own campus, at the initial site or elsewhere.

Representatives of both states and the District say they are trying to keep the contest genteel but fear a nasty political fight.

Ridge spokesman Gordon Johndroe said that no decision has been made and that the process would follow laws governing federal real estate transactions. "This is a new department whose primary mission is security," he said. "It is a very large department, and that presents a number of variables that have to be looked at."

Rep. Thomas M. Davis III (R-Va.) has tried to play down disputes with the District, saying the decision is "too important for parochial politics." Spokesman David Marin said, "Davis will support any decision that will ensure the department can hit the ground running."

Virginians also appear increasingly confident that lower land costs, fewer space constraints and the state's Republican political clout will prevail.

"I don't think we need to lobby for it as much as we need to present the facts as they are," Rep. James P. Moran Jr. (D) said.

Mayor Anthony Williams, shown with President Bush, says Homeland Security headquarters should be in the District.