Longtime neighborhood activist John Fanning plans to launch a primary challenge against D.C. Council member Jack Evans, one of the city’s most powerful politicians, who is now embroiled in an ethics scandal.

Fanning said he plans to file campaign paperwork Monday to become the third candidate to run against Evans (D-Ward 2) in the 2020 Democratic primary.

Fanning, 56, is chairman of a Logan Circle-area Advisory Neighborhood Commission and has worked as a liaison to Ward 2 for several mayors. He resigned as an employee in the D.C. Department of Small and Local Business Development to run for office.

The campaign is shaping up as a rematch: Fanning unsuccessfully challenged Evans in the 2000 primary election.

“A lot of things have changed in 20 years. I’ve matured a lot, and I have accomplished a lot being the chairman of an ANC commission and working in the Mayor’s Office of Community Relations and Services,” said Fanning, whose candidacy was first reported by the Washington City Paper. “I’m best prepared to move the ward forward, particularly when it comes to the business community.”

Evans was first elected in 1991 and is the city’s longest-serving lawmaker. He has indicated that he plans to run for reelection but has not made it official. He did not return a request for comment for this report.

Evans, 65, is the target of a federal grand-jury investigation into his private business dealings with companies affected by District government decisions.

The Washington Post and the news website District Dig have reported that a digital sign company offered Evans stock, consulting fees and a paid summer internship for his son before the lawmaker circulated legislation that would have aided the company. Evans has said that he returned the stock and cash and that his son never took the internship.

The Post also reported that Evans repeatedly used his government email account to send business proposals to potential employers, offering his connections and influence as a lawmaker and chairman of the Washington Metropolitan Area Transit Authority. In response, the council reprimanded Evans and stripped him of some responsibilities earlier this year.

The council and the administration of Mayor Muriel E. Bowser (D) have received federal grand-jury subpoenas for records related to Evans and his constellation of legal and consulting clients. Evans has not been charged with a crime and has denied any wrongdoing.

Evans also faces a separate attempt to recall him from office. Recall proponents have nearly six months to collect signatures from 10 percent of registered voters in Ward 2 — roughly 5,200 people — to force a recall election. If Evans is recalled, the D.C. Board of Elections would call a special election to fill the vacancy, which would probably come shortly before the June 2020 primary election.

Unlike Evans’s other primary challengers, Fanning says he does not plan to spend much time attacking the incumbent on ethics.

“To Jack’s credit, he has done a lot of good things for the ward and he’s dedicated 30 years of his life to public service when he could have done something else,” Fanning said. “But there comes a point in time in one’s career of public service where it’s not such a bad idea to move on.”

Fanning says his campaign will focus on hyperlocal and quality-of-life issues in Ward 2, such as prostitution, homeless encampments and retaining small businesses.

Ward 2 includes downtown, Foggy Bottom, Georgetown, Dupont Circle and Logan Circle neighborhoods. A native of New York, Fanning has lived in Logan Circle for three decades.

The other candidates are Patrick Kennedy, a 27-year-old neighborhood commissioner from Foggy Bottom, and Jordan Grossman, a 33-year-old former congressional staffer and newcomer to D.C. politics.

“What sets me apart from them is my institutional knowledge and my familiarity with the way the government operates, and, of course, I’ve been around and climbed the ladder,” Fanning said.

All are running to the left of Evans, often one of the more conservative members of the council on business and taxation issues. Evans’s challengers also all plan to use the city’s new public campaign financing program, which provides hundreds of thousands of dollars in matching public funds to eligible candidates.

An earlier version of this article incorrectly described John Fanning as former chairman of a Logan Circle-area Advisory Neighborhood Commission. He still holds the post. The article has been updated.