(CNN) - Former South Carolina first lady Jenny Sanford will join gubernatorial candidate Nikki Haley and former Massachusetts Gov. Mitt Romney on the campaign trail Friday for a headline-grabbing final push ahead of next Tuesday's Republican runoff election, a Haley source tells CNN.
Sanford won't have to go far to join the Republican frontrunner - Haley is scheduled to appear with Mitt and Ann Romney in Charleston and Beaufort, both a short drive from Sanford's home on Sullivan's Island.
Sanford gave Haley's campaign its first major endorsement last fall, when Haley, a state representative, was the least known of the four candidates seeking the Republican gubernatorial nomination. Now she is on the cusp of winning the nomination, assuming she maintains her current wide lead in the runoff against Rep. Gresham Barrett.
Haley is regarded as Gov. Mark Sanford's ideological protégé in the governor's race. But the governor, aware of his tarnished reputation in the wake of an affair the destroyed his career and marriage, has avoided endorsing Haley.