The war of words over a proposal to build a large shopping mall next to a Civil War battlefield north of Manassas is getting less civil by the moment, with the latest volley fired in the direction of the National Park Service by the chairman of the Prince William Board of County Supervisors.

In a pointed letter sent recently to Park Service Director William Penn Mott Jr., who is opposed to having a Tysons Corner-sized mall adjacent to the Manassas National Battlefield, Prince William board Chairman Kathleen K. Seefeldt (D-Occoquan) accused Mott of meddling in a local government issue.

"If the National Park Service wishes to protect the area around the battlefield, it should have acquired it," Seefeldt wrote in a letter she released to reporters this week. "Otherwise, the service should confine its activities to matters within its areas of responsibility."

She added that the county board "has acted in what it perceives to be the best interest of the county, and it will continue to do so, and your intrusion is neither useful nor wise."

Mott began the skirmish last month with a letter to Seefeldt in which he expressed "deep concern" that the proposed mall would harm the 3,800-acre park and would represent a failure of the county board to live up to "good-faith agreements" regarding the type of development around the battlefield, off I-66 six miles north of Manassas.

Mott could not be reached for comment yesterday. An assistant, George Berklacy, scoffed at Seefeldt's suggestion that it was inappropriate for the Park Service to voice its concerns about the shopping mall. "We've got every right, and indeed every responsibility, to express our views," he said.

Berklacy also said that building a mall next to the park's hallowed ground "is like booking a roller derby in the Sistine Chapel."

The Hazel/Peterson Companies, a Northern Virginia developer, announced in January a partnership with the Edward J. DeBartolo Corp., the nation's largest builder of shopping centers, to construct a 1.2 million-square-foot mall on a site known as William Center between I-66 and Rte. 29. The development would sit where Confederate Gen. Robert E. Lee had his headquarters during the Battle of Second Manassas in August 1862.

Seefeldt and other county officials have embraced the proposal as a long-awaited bonanza in the financially hard-pressed county's economic development efforts. The supervisors have said the project already has the necessary zoning, requiring no further action by the board.

An angry coalition of local residents and historic preservationists -- joined this week by Carter White House press secretary Jody Powell, who offered the resources of his public relations firm, Ogilvy & Mather, to preserve the site where his ancestors fought -- has pressed the supervisors to reconsider, and Mott did the same in his letter to Seefeldt.

In her riposte, Seefeldt said Prince William had made no agreements with the Park Service that preclude a mall at William Center, and had negotiatiated with Hazel/Peterson to ensure that the development is well-buffered with trees to blunt its visual impact.

Seefeldt said that Mott was in no position to criticize others for neglecting the park in light of what she considers the agency's own dubious actions regarding the battlefield, including a decision, since sidetracked, to build a horse stable on the land, and the service's intention, once financing becomes available, to chop down several hundred acres of mature trees to re-create the battlefield's 1860s appearance.