Middlesex County District Attorney Gerard Leone has decided not to run for the U.S. Senate after all.

Leone told The Boston Globe over the weekend that he was considering a run for the seat left open by John Kerry's resignation to become secretary of state.

Leone, a Democrat, issued a statement Monday saying that while the U.S. Senate is a wonderful public service opportunity, it's not the right next step for him.

Leone has announced he won't seek a third term as district attorney. He said Monday that he remains firm in his decision to leave government service to pursue other opportunities.

The only declared Democratic candidates are U.S. Reps. Edward Markey and Stephen Lynch.

The primaries are set for April 30. The special election is scheduled for June 25.