Tim Chapman, a Democratic candidate for Fairfax County Board of Supervisors chair. (Tim Chapman)

Fairfax County developer Timothy M. Chapman announced Friday that he will loan $725,000 to his bid to become the next chair of the Board of Supervisors in Virginia’s most populous jurisdiction.

The infusion of cash is another sign of how competitive the June Democratic primary election is likely to be. Four Democrats are vying to replace retiring longtime board chair Sharon Bulova (D-At Large) — Chapman, Supervisor Jeff C. McKay (Lee), school board member Ryan McElveen (At Large) and Georgetown University law professor Alicia Plerhoples.

McKay has been seen as the front-runner, raising $135,000 as of Jan. 1, according to the Virginia Public Access Project.

Chapman, a former chair of the Virginia Housing Development Authority, says he offers a more left-leaning agenda and would among other things, push for more affordable housing development and paying teachers higher wages.

“We must boldly lead a progressive and compassionate path starting now,” Chapman said in a news release announcing the loan. “We’re all in. Are you?”

As of January, McElveen and Plerhoples had not yet raised any money for their campaigns, records show. No Republicans have filed to run for board chair.