WASHINGTON - A coalition of Texas community leaders yesterday sued the Department of Homeland Security over the construction of a fence on the Southwest border, saying the department trampled property owners' rights in acquiring land for the project.

The suit, filed in federal district court in Washington, accuses Homeland Security Secretary Michael Chertoff and Homeland officials of violating numerous laws and regulations, and effectively coercing Texas property owners to turn over land for the fence without consultation.

Department officials denied the assertions.

"We've nearly bent over backward to work with landowners," said department spokeswoman Laura Keehner. "Accusations to the contrary are either ill-informed or just plain wrong."

Representatives of the Texas Border Coalition, composed of cities and counties along Texas' 1,200-mile border with Mexico, outlined the lawsuit at a news conference. Peter Schey, the coalition's lead counsel, said he plans to seek a preliminary injunction that would require the government to restart the land-acquisition process, stopping work on at least a portion of the fence.

The lawsuit is the latest, and most extensive, legal action brought against the Bush administration in an attempt to block pedestrian fencing and vehicle barriers that the Department of Homeland Security is building across all four states that border Mexico. It could further complicate the administration's efforts to complete the targeted 670 miles of fencing by Dec. 31.

Environmentalists, with support from more than a dozen members of Congress, are asking the U.S. Supreme Court for a hearing on their contention that Chertoff violated the Constitution by waiving compliance with 36 laws to expedite work on the fence. Chertoff said he was authorized to do so under the Real ID Act of 2005.

Schey accused Chertoff of "lawless conduct" and said Homeland Security ignored border landowners' statutory rights to negotiate reasonable prices for their land before it was seized by the government.

The suit also contends the department gave politically well-connected property owners a pass on having the border fence built on their properties.

The department has gone to court with 86 condemnation suits to gain access to land in Texas, California and New Mexico, including a high-profile case against Eagle Pass, Texas.

Two families in Los Ebanos, a small community in Texas' Hidalgo County, filed an appeal with the U.S. Court of Appeals for the Fifth Circuit challenging a lower court's decision favoring Homeland Security.

Chertoff, named as a defendant in the suit, said the department attempted to negotiate with landowners but was forced to file the condemnation suits against hold-out landowners, who he said were effectively trying to wield a "veto" about the fence.

The department contends it consistently has complied with the law in carrying out the multibillion-dollar project.