Updated

COLUMBIA, S.C. -- South Carolina lawmakers took positions on either side of the first formal move to impeach Gov. Mark Sanford on Tuesday, a day before the release of a pivotal decision into the embattled Republican's travel practices.

Four Republican legislators sponsored a measure that calls for Sanford's impeachment solely based on his five-day trip to see his Argentine mistress in June.

They said his absence, failure to appoint someone to run the state while he was away, and leading staff to believe he was hiking the Appalachian Trail resulted in dereliction of duty and brought "extreme dishonor and shame" on the state.

A top state Republican said heftier allegations would be needed for an impeachment move against the two-term governor, but proponents said they believed Sanford's summertime trip alone amounted to serious misconduct.

"I don't need any more than that," said state Rep. Greg Delleney, the Chester Republican who authored the measure and who for months has called for the governor to step down.

Ben Fox, the governor's spokesman, declined to comment on the measure, which was filed on the first day bills could be introduced for consideration when the Legislature reconvenes in January.

The political maneuvering comes more than four months after Sanford returned from Argentina, admitted to an extramartial affair with a woman he called his soul mate and watched his rising political star fade.

In the ensuing weeks, Jenny Sanford and their four sons moved out of the governor's mansion in Columbia. She is now writing a book about the experience and says the two are separated.

The ethics probe began after a series of Associated Press investigations found Sanford improperly used state aircraft for personal and political trips, flew in pricey seats on commercial flights despite rules requiring low-cost travel and failed to report trips he'd taken on private planes.

A onetime prospect for the 2012 GOP presidential nomination whose term expires in January 2011, Sanford has brushed off numerous calls for his resignation from state Republicans. But the blows have been cushioned by time and progress on economic development, most notably a decision by Boeing Co. to locate an aircraft assembly line in North Charleston.

Still, many lawmakers have said they would wait on the outcome of the State Ethics Commission investigation. On Wednesday, the commissioners -- all either appointed or reappointed by the governor -- are expected to decide whether Sanford should face criminal or civil charges or be cleared of wrongdoing.

House Speaker Bobby Harrell on Tuesday sent the impeachment measure to the Judiciary Committee for consideration, but said he believes the accusations from lawmakers and the media alone do not merit impeachment.

"Unless the investigation contains new information about serious crimes or serious misconduct by the governor, in my opinion, the information we have to date does not rise to a level to remove him from office," Harrell, R-Charleston, said in a statement. "The Ethics Commission's investigation will be used as the basis to determine whether or not the governor's actions rise to that level."

An impeachment proceeding would be brought in the House. If two-thirds agree, Sanford would be suspended and the Senate, serving as a jury, would then decide if he is permanently removed from office.

Meanwhile, the public's access to details of Wednesday's ethics commission decision on whether there is probable cause for the governor to face sanctions is mired in legal action.

Harrell has asked for a clarification of the state Supreme Court's Nov. 5 ruling that said Sanford had waived rights to confidentiality in the ethics investigation.

On Nov. 9, the House asked the Ethics Commission to provide a copy of the report as soon as Sanford received it, but the commission said it had yet to decide how to handle a Sanford request that the report be kept secret.