Senate Minority Leader Mitch McConnell (R-Ky.) on Thursday appointed Sen. Mel Martinez (R-Fla.) to serve as a leadership counselor in his office.

Martinez replaces Sen. Lisa Murkowski (R-Alaska), who was named as one of three of McConnell’s counselors earlier this year. Murkowski was elected to be vice chairwoman of the Senate Republican Conference in the wake of Sen. John Ensign’s (R-Nev.) sex scandal, which has prompted a shake-up in the leadership.

Ensign had been the GOP policy chairman, a position he relinquished after admitting to an affair with a former campaign staffer. On Thursday, Sen. John Thune (R-S.D.) was elected to replace Ensign, and Murkowski moved into Thune’s old job as Conference vice chairwoman.

“I’m honored to add my voice on how we address the great many issues facing our nation. We’re still in the thick of a housing crisis, an economic recession, and mounting government debt. We need to address these issues in an expedited and reasoned fashion,— Martinez said.

Martinez is retiring in 2010 after just one term in the Senate. As a counselor to McConnell, he will join Sens. Judd Gregg (N.H.) and Bob Bennett (Utah) in providing “input, guidance, and advice to the Republican leadership,— according to a statement from Martinez’s office.