The worst-kept secret in District politics is official: Ward 6 Councilman Tommy Wells is moving toward a run for mayor next year.

Wells, who first told the Northwest Current in July that he might seek the city's top job, said Monday that he had formed an exploratory committee. Although Wells said the committee's founding does not guarantee he'll mount a campaign, he has said it is "likely" he will run in the Democratic primary, scheduled for April 2014.

"Our city is at a crossroads. We need to sustain our progress in building livable, walkable communities with safe streets, great schools, accessible transit and neighborhood small businesses for every District resident," Wells said in a statement formally announcing the exploratory committee. "Our continued momentum depends on restoring integrity to our elected government with ethical leadership focused on one thing: creating a great city."

Wells is beginning his campaign Monday night with an event in Anacostia.

Wells is the first person to file papers to explore a run, though more are expected. Ward 2 Councilman Jack Evans and Ward 4 Councilwoman Muriel Bowser are among the potential candidates weighing whether to run.

Incumbent Mayor Vincent Gray, whose two-year tenure has been plagued by a federal investigation of his campaign, has not said whether he will seek a second term.