It was perhaps one of the most short-lived endorsements that Senator Joseph I. Lieberman has received in his independent quest for re-election.

On Wednesday night, the two United States Senate candidates in New Jersey addressed several hundred people at Temple Beth Shalom in Livingston, N.J., as part of a forum sponsored by the Metro West Jewish Federation.

During their hourlong sessions, Senator Robert Menendez, the Democratic candidate, and his Republican opponent, State Senator Thomas H. Kean Jr., were asked about Mr. Lieberman, who declared his independent candidacy in Connecticut after being defeated in a Democratic primary by Ned Lamont.

In a written question from an audience member, Mr. Menendez was asked why he supported Mr. Lamont. Mr. Menendez said that his support of Mr. Lamont was a “mischaracterization,” adding that he supported Mr. Lieberman’s run as an independent candidate.

“I wish him well and hope he returns,” he said.

With that, Mr. Menendez — who 24 hours earlier had been engaged in a tense radio debate with Mr. Kean — warned the crowd that Mr. Kean, who was to speak next, would try to tell the crowd that Mr. Menendez supported Mr. Lamont.

About 40 minutes later, when Mr. Kean was asked about Senator Lieberman — who despite his independent candidacy said he would continue to caucus with Democrats — said, “I think he is the right individual and I look forward to serving with him.”

After a pause, he added, “My opponent, by the way, supports Ned Lamont.”

It appeared that Mr. Kean had played right into his opponent’s hands.

But yesterday morning, after the two New Jersey candidates’ comments were posted on the “Empire Zone,” a New York Times political blog, a spokesman for Mr. Menendez called this reporter and asked that the senator’s comments be changed.

“What he was meaning to say is that he has enjoyed working with Senator Lieberman and looks forward to serving with him should he be re-elected,” said the spokesman, Matthew Miller. “But his official endorsement is for Lamont, and he supports the party.”

Most national Democratic Party leaders are at least publicly backing Mr. Lamont. But Mr. Lieberman, a three-term senator and vice presidential candidate in 2000, has support from a handful of Democratic colleagues. On Wednesday, Representative Harold Ford Jr., the Democratic Senate candidate in Tennessee, said he would support Mr. Lieberman.

Some Republicans have backed Mr. Lieberman as well. For instance, Senator Susan M. Collins, a Republican from Maine, is scheduled to appear with him this afternoon.

When asked why Mr. Menendez had endorsed Mr. Lieberman at the synagogue but tried to back off the next day, Mr. Miller would only say that Mr. Menendez supported the Democratic nominee.

Not surprisingly, the Kean campaign jumped all over Mr. Menendez.

“Bob Menendez went before a group of concerned Jewish voters and tried to hoodwink them,” said Jill Hazelbaker, a spokeswoman for Mr. Kean.