With Additional Reporting By Julian Hattem

Former DNC Chair Howard Dean called on Sen. Joseph Lieberman (I-Conn) to resign as chair of Senate Homeland Security Committee if he can’t bring himself to oppose a Republican filibuster of health care reform legislation.

Appearing on “The Joe Scarborough Show” on WABC, Dean stressed that he had no problem with Lieberman opposing the bill on its philosophical merits, or lack thereof. But he insisted that it was irresponsible and unprincipled to not allow the legislation to come to an up-or-down vote.

“I think that [Lieberman] is a very complicated guy,” said Dean. “He does [confuse me] because he says he’s a principled guy but there’s nothing principled about holding up a bill… If he was a principled guy he’d resign his chairmanship.”

“If you are with a caucus you don’t owe the leader any vote on any substance,” Dean added. “I have no problem with him voting against the public option… You owe it to Harry Reid to allow him to run a Senate. And if you’re not willing to do that the proper thing to do is to step aside.”

Dean’s remarks, which come after Lieberman renewed his pledge to filibuster health care reform that includes a public option, reflect an intense frustration among progressives over the ability of moderates to water down or stall legislation. They also suggest a growing demand for leadership to enforce institutional discipline and punish those who buck the party line. It was, after all, roughly one year ago that Dean applauded Senate Majority Leader Harry Reid (D-Nev) and President-elect Obama for allowing Lieberman to retain his committee chairmanship and continue caucusing with the party.

Elsewhere in his Wednesday interview, the former DNC chairman urged the party to reconsider the use of reconciliation to pass aspects of reform. Such a parliamentary maneuver, he noted, would remove the “leverage” of the party’s conservative members by allowing the bill an up-or-down vote.

“[Lieberman has] announced he’s gong to be “stubborn” about this,” said Dean, “and I think that means going to reconciliation. You can start it all over and that’s going to take about six weeks, but there are a majority of senators who are not going to be in favor [a bill] without a public option.”