The U.S. Chamber of Commerce on Thursday endorsed Rep. Jack Kingston (R-Ga.) in the crowded Republican primary for U.S. Senate in the Peach State.

"Now more than ever we need conservative leaders with a demonstrated record of fighting for Georgia jobs, and that leader is Jack Kingston. As senator, Jack will help lead America’s comeback and lay the groundwork for more jobs, more growth, and a generation of prosperity," said Rob Engstrom, the business group's political director.

The chamber's endorsement is important because the group has been known to spend significant money on behalf of candidates it supports.

Kingston is part of a competitive Republican field that also includes Reps. Paul Broun and Phil Gingrey, former secretary of state Karen Handel and businessman David Perdue. Handel is backed by Sarah Palin while Gingrey has faced negative ads from the super PAC Ending Spending Action Fund. The super PAC has not publicly lined up behind any candidate in the race.

The primary is May 20. Most observers expect a top-two GOP runoff, which would be triggered if no candidate wins a majority of the vote.

The likely Democratic nominee is Michelle Nunn, a first-time candidate who has been raising big money since entering the race last year.