James H. Dean, brother of Howard Dean, chairman of the Democratic National Committee, lives in Connecticut and heads Democracy for America, a group that is gathering signatures on the Internet for a letter that criticizes the senator.

An aide to James Dean said he and others from the group would deliver the letter to Mr. Lieberman's office in Hartford on Tuesday. The aide said the letter had 30,000 signatures.

Other Democratic activists warned that they might try to organize
a primary challenge against Mr. Lieberman, specifically because of his position on the war.

Tom Matzzie, the Washington director for MoveOn.org, a liberal
advocacy group with 10,000 members in Connecticut, said it would consider a challenge if the right candidate came along.

"It's like a betrayal," Mr. Matzzie said of Mr. Lieberman's stand on the war.

¶ 6:47 PM