Kentucky Senate candidate Trey Grayson (R) will be able to trumpet the endorsement of the U.S. Chamber of Commerce during the final week of the primary campaign. His campaign announced Tuesday it had the backing of the influential business group.

The Chamber said it was Grayson's support of "pro-business issues" that got him its nod.

"If I'm elected I will fight for a balanced budget and economic policies that will free small businesses and entrepreneurs to expand their businesses, innovate and create jobs," Grayson said in a statement.

He also was endorsed last week by Senate Minority Leader Mitch McConnell (R-Ky.)

Grayson faces Dr. Rand Paul in the May 18 GOP Senate primary.