The wave of opposition to the nation’s civil asset forfeiture laws grew a little larger on Tuesday as advocacy groups spoke out in favor of legislative reforms supported by members of both political parties.

The National Association of Criminal Defense Lawyers sent a letter to every office on Capitol Hill, expressing support for proposals to stop police from seizing cash, cars and other property from people without compelling evidence of a crime.

The American Civil Liberties Union also issued a strong statement on Tuesday, saying legislation is needed to protect innocent Americans from a seizure system that has a disproportionate effect on low-income people.

Under a program at the Justice Department called Equitable Sharing, federal authorities have been allowed to share in the proceeds of seizures made by local and state police.

“We can no longer ignore the conflicts of interest and policy problems that arise when law enforcement and prosecutorial agencies reap financial bounty from the forfeiture decisions they make,” NACDL President Theodore Simon said in a letter to lawmakers.

A Washington Post investigation last year found through an analysis of Justice data that local and state police had taken $2.5 billion in cash from drivers and others under federal law since Sept. 11, 2001, without warrants or indictments. The seizures were processed through the Equitable Sharing Program.

A cross-section of lawmakers has come out in favor of reforms, including Sens. Charles E. Grassley (R-Iowa), Patrick J. Leahy (D-Vt.) and Rand Paul (R-Ky.) as well as Reps. James F. Sensenbrenner Jr. (R-Wis.), Tim Walberg (R-Mich.) and others.

On Jan. 16, Attorney General Eric H. Holder Jr. prohibited federal agencies from “adopting” local and state seizures into the Equitable Sharing Program.

Holder’s changes left open the possibility of local and state seizures, but only those “resulting from joint operations involving both federal and state authorities” or “seizures pursuant to warrants issued by federal courts.”

In its statement Tuesday, the NACDL said more reforms are needed, including sharper limits to Equitable Sharing than those Holder announced.

The group sent its letter to support reform legislation introduced Tuesday by Paul and Walberg.

The bill, called the Fifth Amendment Integrity Restoration Act, or Fair Act, is a reprise of legislation offered last year.

It would raise the level of proof needed to make a seizure and abolish Equitable Sharing.

In a news conference, Walberg drew attention to the bill’s support from lawmakers in both parties and from members of both the Senate and the House.

“This is of significant interest to a lot of people — called citizens of the United States,” Walberg said. “Politically and philosophically, there is a unifying of diverse points of view.”

Kanya Bennett, ACLU legislative counsel, said the legislation “offers the most comprehensive federal reform right now to end the seizing of innocent Americans’ property.”

Bennett said the law is “especially significant because this practice often goes hand in hand with racial profiling and disproportionately impacts low-income people who don’t have the means to challenge the government’s taking — putting our civil liberties and property rights under assault.”

But other reform legislation is expected to be introduced this year by Grassley, chairman of the Senate Judiciary Committee, and Leahy, the committee’s ranking Democrat.

Sensenbrenner launched an investigation of Equitable Sharing in the fall and has said he intends to offer a comprehensive bill of his own soon.

“Sufficient forfeiture reform is long overdue.” Sensenbrenner said Tuesday.

“I commend Senator Paul and Congressman Walberg for their work on the Fair Act and look forward to working with them as we move forfeiture reform through the House and Senate judiciary committees and onto the floors of Congress.”