COLUMBIA, S.C. — South Carolina's lieutenant governor will ask embattled Gov. Mark Sanford to resign at a news conference Wednesday, a spokesman said.

Lt. Gov. Andre Bauer will agree to stay out of next year's governor's race if Sanford steps down, an offer he first made in June after his fellow Republican admitted a yearlong affair with an Argentine woman.

"People need to take their personal, political considerations off the table and think about what's best for the state," Bauer spokesman Frank Adams said.

Sanford has previously said he has no plans to resign. His spokesman did not immediately return a call Wednesday.

Bauer, who was widely expected to run for governor in 2010, is now the most prominent Republican calling for Sanford to resign. Sanford can't run again because he is limited to two terms.

Supporters of other candidates have been wary of asking Sanford to step down because they did not want to give Bauer a long-term tryout for the state's top job.

Sacrificing the run for governor next year could boost Bauer's status in the state GOP but still allow the 40-year-old plenty of time for another election. His announcement comes a day after the first formal gubernatorial campaign news conference by Republican Attorney General Henry McMaster.

Bauer has always been Sanford's lieutenant governor, but South Carolina voters choose the officials separately and the two have had a rocky relationship. Some of Bauer's friends in the Legislature are among Sanford's biggest critics and Sanford's estranged wife supported a Bauer opponent in the 2006 GOP primary.

Sanford has come under scrutiny since he returned from a nearly weeklong disappearance in June to admit he had been in Argentina visiting his mistress. His staff had been led to believe he was hiking the Appalachian Trail.

In a series of investigations since the governor told The Associated Press his mistress was his soul mate, the AP has found Sanford used state plans for personal and political trips, which state law prohibits. He also failed to disclose trips on private plans that ethics officials say should have been made public in campaign and ethics filings.

An AP investigation in July showed the governor took pricey flights on commercial airlines for overseas trips despite a law requiring state employees to use lowest-cost travel. A state senator investigating those flights has said six of them broke the law and the state attorney general has called for an ethics probe.

The governor says he has done nothing wrong and claims the AP has mischaracterized his flights on private planes. He says he flew in more expensive seats on commercial flights because he needed to be well rested on economic development trips, which other governors have done. His office also has claimed the law restricting such use is no longer valid.