Carter entered the race in July. (Mike DeBonis/The Washington Post)

The mayoral field for the upcoming Democratic primary unexpectedly took final shape Saturday when Christian Carter, a businessman who entered the race in July, announced at the Ward 8 Democrats candidates forum and straw poll that he was dropping out of the race.

“I put my voice out there, and I’m going to continue to move forward and explore other options,” Carter said, adding, “I’m not going to waste your time talking. I’m going to let these candidates continue to run and move forward, and we’ll be looking at and watching you guys.”

Carter, who has done work for the city as a staffing consultant, entered the race in July amid questions about payments to his subcontractors and an unpaid bill for office rent. Since then, his campaign message focused on combating the displacement of longtime city residents and improving the city’s relations with its contractors has failed to catch on: A Washington Post poll released last week found he garnered only minuscule support.

Carter was also facing two challenges to his ballot petitions, meaning he would have had to defend the legitimacy of the signatures he gathered to the Board of Elections in the coming weeks in order to continue his campaign.

Because Carter was the only mayoral candidate to have his signatures challenged, his departure means the Democratic field is now set for the April 1 primary. Incumbent Vincent C. Gray will face off against D.C. Council members Muriel Bowser (Ward 4), Jack Evans (Ward 2), Vincent B. Orange (At Large) and Tommy Wells (Ward 6), as well as former federal official Reta Jo Lewis, restaurateur Andy Shallal and entrepreneur Carlos Allen.

Any of those candidates could still drop out of the race, but they are guaranteed to remain on the ballot unless they withdraw before Feb. 7. If candidates withdraw after that, they will remain on the ballot, though signs will be posted at polling places informing voters of any withdrawals.

Feb. 7 is also the day that the elections board will hold a lottery to determine the order of candidates on the ballot.