Muriel Bowser (second from left) is gaining on Vincent Gray (right), a new poll shows. (Marvin Joseph/The Washington Post)

A new D.C. mayoral poll shows incumbent Vincent C. Gray maintaining a lead in the race for the Democratic nomination, but most voters continue to prefer other candidates, with D.C. Council member Muriel Bowser (D-Ward 4) opening a lead over her fellow challengers.

The survey released Tuesday night by WRC-TV, WAMU-FM, The Washington Informer and Marist College is the first mayoral-race polling to be publicly released since The Washington Post published survey results on Jan. 14.

As in the Post poll, Gray holds a significant lead among likely voters in the newer polling. But while the previous numbers showed three D.C. Council members — Bowser, Jack Evans (D-Ward 2) and Tommy Wells (D-Ward 6) — running roughly even, with about half Gray’s support among registered Democrats, the new poll shows Bowser opening a lead over Evans and Wells.

Among likely voters, Gray has 28 percent support, followed by Bowser with 20 percent, Evans with 13 percent and Wells with 12 percent. Other candidates lag significantly: Restaurateur Andy Shallal has 6 percent, Council member Vincent Orange (D-At Large) has 4 percent, and former State Department official Reta Jo Lewis has 3 percent. The reported margin of error among likely voters is plus or minus 4.8 percentage points.

The poll reached 1,138 adults via both cellphone and land line between Feb. 17 and Feb. 23. Of those, 416 were identified as likely voters in the April 1 primary.

Much as in the Post poll, the new survey offers good news and bad news for Gray. Among all residents, he enjoys a strong job approval rating (56 percent) and a widespread feeling the city is on the right track (71 percent). But 60 percent of all residents and 62 percent of registered voters would prefer a new mayor. Among registered Democrats, nearly half (46 percent) say they believe Gray was involved in unethical actions related to his 2010 campaign, while 24 percent believe he was involved in something illegal. The remaining 30 percent split evenly between those who believe he did nothing wrong and those who are unsure.

The new polling comes with five weeks remaining until Election Day, with just under three weeks remaining until early voting begins. Bowser is likely to seize on her strength relative to her fellow challengers to forward a campaign narrative that she is best positioned to unseat Gray as the Democratic nominee. Notably, she was endorsed by the Washington Post on Feb. 20, about halfway through the survey period, meaning the endorsement’s effect might not be fully reflected in the final tally. Also, Gray and Orange received some union endorsements during and after the poll was in the field.

Scott Clement contributed to this report.