The Democrat-turned-Independent senator from Connecticut caucuses with Democrats and heads the Homeland Security and Governmental Affairs Committee. The Hill reported Wednesday that a spokesman for Senate Majority Leader Harry Reid, D-Nev., indicated Lieberman could lose one or both of those opportunities.

Lieberman gave a speech Tuesday that was critical of Democratic presidential candidate Sen. Barack Obama of Illinois. Lieberman, the 2000 Democratic vice presidential candidate, is a supporter of Sen. John McCain of Arizona, poised to become the Republican presidential candidate.

Stressing no decision is pending, Reid spokesman Jim Manley said "it's likely" that Democrats will caucus after the November elections to decide Lieberman's fate.

"He has every right to make a partisan speech at the Republican National Convention if that's what he wants to do," Manley said. "Having said that, that doesn't give him the right to question Obama's role and record in the Senate in the speech."