One of Illinois’ most powerful Democratic lawmakers announced Monday that he had resigned to take a job as a lobbyist, just days before he was to be sworn into his new term in the General Assembly.

Illinois State House Majority Leader Lou Lang, D-Skokie, announced his resignation as effective last Wednesday.

Lang will join Advantage Government Strategies LLC, a government affairs firm led by Nancy Kimme, a prominent fixture in the Springfield lobbying corps.

“One enduring feature of any legislative career in Springfield is transition – entering and leaving the legislature. For me, I too will be part of this year’s transition,” Lang said in a news release. “Rather than beginning a 17th term in the 101st General Assembly, I have decided to resign my seat effective today, Jan. 2, at noon.”

The 16-term lawmaker was appointed to the House in 1987 and was seen as a probable successor to longtime House Speaker Michael Madigan.

Lang came under fire after allegations of sexual harassment by Maryann Loncar last May. She said the prominent lawmaker leveraged his position to harass and intimidate her for years after initially working together on a 2013 medical marijuana bill. Lang was later cleared of wrongdoing, in part because Loncar declined to talk to the Legislative Inspector General investigating the allegations.

He will remain in his political position as a committeeman for the Niles Township Democratic Organization and Executive Vice Chairman of the Cook County Democratic Party.

Local Democrat leaders from Suburban Cook County will choose a successor to the 16th House District. Leaders will interview those interested in seeking the post, according to Lang’s news release. Because he’s keeping his post in the local township Democratic organization, Lang will likely have a say in who succeeds him.