The measure calls for formation of a federal task force to combat "the unique set of crimes committed by polygamist organizations."

It also would make available $2 million in federal grants for local authorities to investigate and prosecute crimes linked to polygamy. Another $12 million over five years would be offered to organizations that provide protection and services to family members seeking to escape plural marriages.

Former members of polygamous groups have charged domestic and sexual abuse is common through forced marriages and unions involving underage girls, along with other crimes such as welfare fraud, tax evasion, extortion and kidnapping.

Reid, the Senate majority leader from Nevada, has equated activities of polygamist groups with organized crime and has been pressing for federal racketeering investigations of their activities.

The Senate hearing is expected to focus on the Fundamentalist Church of Jesus Christ of Latter Day Saints, a breakaway Mormon sect whose adherents believe plural marriage is ordained by God. The mainstream Mormon church renounced polygamy in 1904.

FLDS membership is based in communities on the border of Utah and Arizona, while members also live in Nevada and other Western states. Its membership is estimated to be between 6,000 and 10,000.

State and local authorities have pursued criminal allegations against FLDS leaders and members, while Reid has argued a stronger federal hand is necessary.

FLDS leader Warren Jeffs was convicted in Utah last year of two counts of being an accomplice to rape, for his role in arranging a 2002 marriage between a 14-year-old girl and her 19-year-old first cousin.

Jeffs faces similar charges in Arizona and this week was indicted by a grand jury in Texas on sexual assault charges.

"We are taking aim at the blatant and systemic crime that is rampant within these polygamist groups," Reid said in a statement accompanying his bill.

Reid, one of 16 Mormons serving in Congress, did not consult with the church in forming his bill, according to his spokesman Jon Summers.

The Mormon church has not taken a position on the bill, spokeswoman Kim Farah said. In an e-mail, she said "The Church of Jesus Christ of Latter-day Saints has repeatedly expressed concern about the illegal practice of polygamy and persistent reports of the possible emotional and physical abuse of women and children."

Today's hearing is entitled "Crimes Associated with Polygamy: The Need for a Coordinated State and Federal Response."

Chief federal prosecutors from Nevada and Utah are scheduled to testify along with attorneys general from Arizona and Texas. Also listed to testify are former FLDS member Carolyn Jessup, and Stephen Singular, who has written about the FLDS and Jeffs.

The Salt Lake Tribune reported that FLDS spokesman Rod Parker, a Salt Lake City attorney, sent the Senate Judiciary Committee a letter protesting that no members of the group were invited to testify.

"History is replete with examples of misinformation becoming the foundation of persecution and hysteria, leading in turn to real harm to real people," Parker wrote, according to the newspaper.

Parker could not be reached by telephone message or e-mail on Wednesday.

Asked why there were no FLDS witnesses invited, Summers said the committee did not need to hear from them.

"This is not a trial," Summers said. "This is a hearing about ways to increase enforcement against crimes committed by these groups. Are they going to come in and say this is the best way to bust us?"

Contact Stephens Washington Bureau Chief Steve Tetreault at stetreault@ stephensmedia.com or 202-783-1760.