Dennis M. Callahan, the former mayor of Annapolis and the director of Anne Arundel County's recreation and parks department, is expected to declare his candidacy for county executive today at Crofton Country Club.
Callahan would not comment before his announcement. But officials at the country club confirmed that he will make a "political announcement" at the clubhouse at noon.
Fellow Democrats have expected for several months that Callahan, 64, would step forward to challenge county Sheriff George F. Johnson IV for the party's nomination.
"When he enters the race, he will give 100 percent toward his effort, trying to defeat George Johnson in the primary, but he has a formidable challenge ahead of him," said Carl O. Snowden, an aide to County Executive Janet S. Owens.
Snowden served alongside Callahan in late 1980s as an Annapolis alderman and lost to Callahan in the 1997 Democratic primary for Annapolis mayor by 155 votes.
Five Republicans also are in the race to replace Owens, a Democrat, who cannot run for a third term.
Callahan would enter a primary race against a clear frontrunner in Johnson, who reported that he raised more than $372,000 last year and has more than $318,000 on hand.