Northup, who was defeated by Rep. John Yarmuth (D-Ky.) last November, is challenging sitting Republican Gov. Ernie Fletcher in the primary.
Fletcher’s first term has been marred by indictments and subsequent pardons of administration officials amid charges of unethical hiring practices. As a result, Northup has been picking up a lot of Republican support throughout the state.
Fletcher went on the air last month; the other Republican in the race, businessman Billy Harper, is planning to air ads next week as well.
Northup campaign spokesman Barry Peel said the campaign was declining to specify how big the ad buy would be or how much the campaign was spending.