Rep. John Barrow (D-Ga.) is giving a run for the Senate "serious consideration," he told supporters in an email.

Barrow, a centrist Blue-dog Democrat, may be his party's best chance to win the open Senate seat. He has held on to his Republican-leaning seat through a series of tough elections.

The email, which invites supporters to a small fundraising luncheon, is the bluntest the famously cautious politician has been about his interest in the race.

"Some have suggested that I run for the United States Senate to replace the retiring Senator Saxby Chambliss, and I would appreciate your thoughts as I give this serious consideration," Barrow writes at the end of the email. "I've asked my top campaign advisors to present to you how we believe the next few years will unfold politically, and how we can meet the challenges ahead."

The fundraising email was first obtained by the Atlanta Journal-Constitution.

Sources with knowledge of Barrow's thinking have told The Hill in recent days that he's leaning toward a Senate run rather than a tough reelection battle for his House seat, but wants to make sure he'll have a clear primary field and firm financial commitments from the Democratic Senatorial Campaign Committee before making a decision.