Hours after resigning from the Maryland state senate, Nathaniel T. Oaks on Thursday pleaded guilty to public corruption charges.

Oaks, a longtime Democratic lawmaker from Baltimore, admitted in federal court that he accepted more than $15,000 in bribes from a man he thought was a real estate developer, in exchange for help securing funds for a project.

He is set to be sentenced July 17 in federal court in Baltimore.

Late Wednesday night, Oaks, 71, submitted a letter of resignation to Senate leadership saying he had decided to step down “to eliminate all clouds that have hovered over the 2018 Legislative Session.”

“Due to any potential concerns or questionable activities on my behalf, it is with deep regret, respect and all my love for Baltimore City, the Maryland General Assembly, its leadership, my ­legislative colleagues and my constituents in the 41st District, that I resign my position,” Oaks said.

Oaks is the second Maryland lawmaker embroiled in a federal corruption scandal to resign in the past two years. Former state delegate Michael L. Vaughn (D-Prince George’s) resigned on the first day of the 2017 legislative session. He was later charged and found guilty earlier this month of conspiracy and bribery for accepting cash in exchange for votes to expand liquor sales in Prince George’s County.

Prosecutors said Oaks used his power as a legislator to help a real estate developer known as “Mike,” who was interested in a housing development project in Baltimore. The developer turned out to be an undercover FBI source. In exchange for cash bribes, Oaks filed a request for a bond bill with the Maryland Department of Legislative Services to secure funding for the project. He also admitted to filing statements he knew to be false in a letter asking for federal funds for the purported development.

After accepting bribes in 2016, Oaks confessed to the FBI after arriving at a Baltimore hotel in early 2017 expecting to meet the developer but instead facing two FBI agents, his plea states.

Oaks agreed after that encounter to wear a recording device in an FBI investigation of another businessperson with interests in the bail bond and health-care industry. That person had previously given Oaks money for car repairs and paid for short trips to Las Vegas and dinners as Oaks helped build support for legislation in the person’s interest, the Oaks plea agreement states.

But after several months of helping the FBI in a “covert public corruption investigation,” Oaks admitted in his plea, he tipped off the businessperson, which meant the federal investigation into that person “and possibly other politicians was no longer viable,” prosecutors wrote in the Oaks plea deal.

Oaks had appeared determined to remain in office despite repeated calls for his resignation from Gov. Larry Hogan (R) and some of his colleagues. Last month, he filed for reelection.

Oaks was stripped of his committee assignment last month after the Joint Committee on Legislative Ethics found “numerous potential violations of the Maryland Public Ethics Law,” including the misuse of public resources, conflicts of interest, misuse of the prestige of office, improper acceptance of gifts, failure to make required disclosures and failure to register as a lobbyist. The committee took the action after referring to the criminal complaint and “other related documents.”

Oaks, who has served in the General Assembly for 30 years, was charged in federal court on April 7, a Friday. He shocked his colleagues the following Monday, April 10 — the final day of the session last year — when he walked into the Senate chamber and took his seat.

He lost his seat in the House of Delegates in the late 1980s after being convicted of stealing thousands of dollars from his campaign account. He regained his seat in 1994 and was appointed to the state Senate last year to replace a legislator who stepped down because of ill health.

Oaks faces a maximum of 20 years each on charges of wire fraud and honest services wire fraud.

Oaks and his attorney could not immediately be reached for comment Thursday.