Brown stumped with an activist who helped write a 1998 report for the Interior Department documenting forced abortions, exploitation of foreign workers and other grim conditions on the Marianas, a U.S. commonwealth near Guam. Residents there have nonvoting citizenship, but the islands are exempt from many federal labor laws and the minimum wage is $3.05 an hour.

The Marianas hired now-disgraced lobbyist Jack Abramoff in the mid-1990s to block reform legislation, and Abramoff lobbied lawmakers, including Doolittle and Rep. Richard Pombo, R-Tracy, for help.

Doolittle, who traveled to the Mariana Islands in 1999, subsequently spoke favorably of conditions there and opposed bills to raise the minimum wage and impose U.S. immigration laws.

Doolittle, who has taken $14,000 in campaign contributions from Abramoff, also helped the lobbyist get his contract with the Marianas renewed in 1999 by endorsing a sympathetic island politician. Abramoff is now cooperating in a wide-ranging congressional influence-peddling investigation.

"John Doolittle and others like him in our Congress have lost their moral authority to lead because they've sold out the American people just as surely as they sold out the women and children in the Marianas," Brown, a retired Air Force lieutenant colonel, said during a news conference.

Activist Wendy Doromal wept as she recounted abuses that included indentured servitude, forced abortions, rape and false imprisonment.

"What we're allowing in the Marianas is clearly wrong, but John Doolittle continues to insist that he didn't see any abuses over there," Brown said.

Doolittle's spokesman dismissed the claims, which the Brown campaign also has been using in radio advertisements.

"The suggestion that Congressman Doolittle tolerated forced abortions and sex slavery is so ludicrous that it can't help but undercut Brown's credibility with the voters," spokesman Richard Robinson said. "I think he's officially become the candidate that will do or say anything to get elected."

While visiting the Marianas, Doolittle witnessed "an unfettered, free-market system that resulted in clean and orderly factories and employees who expressed personal satisfaction with their jobs," said a statement from Doolittle's congressional office.

The congressman has an ongoing interest in the commonwealth that has nothing to do with Abramoff, Robinson said.