Despite Joe Wilson's personal apology to the president for heckling him as a liar during his address to Congress last night, there is growing discontent within House Democratic leadership ranks over Wilson's refusal to officially apologize on the House floor.

According to officials sitting in on a leadership meeting in Speaker Nancy Pelosi's office Thursday afternoon, Democratic Whip Jim Clyburn (S.C.) told his colleagues that he approached Wilson - a fellow South Carolinian - three times during a vote earlier today asking Wilson to formally apologize for calling out "You Lie!" as Obama spoke in the House Chamber on healthcare reform.

It is against the House rules to impugn the integrity of the president when speaking on the floor or in committee meetings.

House leadership, including GOP leader John Boehner (Ohio), talked to Wilson during today's vote, which was kept open for a longer than normal period of time so that Wilson would have a chance to say "I'm sorry."

Despite Clyburn's efforts, Wilson refused to make an apology on the floor.

When asked about the conversation on the floor, Boehner told reporters that "he did have a conversation with Mr. Wilson. I'm not going to relay the contents of my private conversation with him."

As for whether Wilson should apologize in the chamber, Boehner responded "I think that Mr. Wilson made it clear that he said his behavior was inappropriate, and he apologized [to the President] for it. And I'm glad he did."

Though Wilson called the president last night to apologize for his outburst (which he insists was unintentional), Clyburn and other Democratic leaders, including top House appropriator Jack Murtha (D-Penn.), want to hear the normally mild-mannered conservative say the words "I'm sorry" to his House colleagues.

If not, the House "should take some action," said Murtha.

The House's second-ranking Democrat, Majority Leader Steny Hoyer (Md.) left open the possibility of pursuing formal action against Wilson.

Hoyer told the Hill that he would wait to see what Wilson would do but suggested that apologizing to the president was not enough. Hoyer said he was offended that a member of Congress brought "disrespect to the House of Representatives because the president was here as a guest of the House and Senate to speak at a joint session."

Earlier Thursday, Speaker Pelosi ruled out an official censure of Wilson. However, there are other options to pursue.

Clyburn's office is currently reviewing various action to take when a member of Congress breaks the House's code of conduct and may either draft a "resolution of disapproval" or pursue a reprimand of Wilson.

A reprimand is a punishment less serious than a censure but is more than a slap on the wrist, explained a leadership aide.