Lieberman, a Connecticut independent, currently is the target of liberal wrath over his opposition to a government-run insurance plan in the health care bill.
Franken was presiding over the Senate Thursday afternoon as Lieberman spoke about amendments he planned to offer to the bill. Lieberman asked for an additional moment to finish -- a routine request -- but Franken refused to grant the time.
"In my capacity as the senator from Minnesota, I object," Franken said.
"Really?" said Lieberman. "OK."
Lieberman then said he'd submit the rest of his statement in writing.
Republican Sen. John McCain of Arizona came to his friend Lieberman's defense, saying he'd never seen such a thing occur.
"I must say that I don't know what's happening here in this body but I think it's wrong," McCain said on the floor.
Franken's spokeswoman, Jess McIntosh, said that the Minnesota senator wouldn't allow Lieberman to continue because time limits were being enforced by Senate leaders rushing to finish a defense spending bill and get to the health bill.