Former Illinois House Speaker Michael Madigan announced Thursday he will resign the seat he’s held for half a century at the end of the month.

In a lengthy statement, Madigan said it was an honor to “serve the people of Illinois as speaker of the House and state representative of the 22^nd District” and took aim at the “vicious attacks” by people who “sought to diminish my many achievements lifting up the working people of Illinois.”

“Fifty years ago, I decided to dedicate my life to public service,” Madigan said. “Simply put, I knew I wanted to make a difference in people’s lives. I believed then and still do today that it is our duty as public servants to improve the lives of the most vulnerable and help hardworking people build a good life. These ideals have been the cornerstone of my work on behalf of the people of Illinois and the driving force throughout my time in the Illinois House.”

Madigan said he was “particularly proud” of the work of the House Democratic Caucus to increase the diversity of voices in the house to “include more women, people of color and members of the LGBTQ community.”

“In my tenure as Illinois House speaker, we worked to elect representatives across all backgrounds and beliefs to truly represent the interests of the people of our state,” the statement continued.

Madigan’s reign as the longest-serving leader in state or federal government ended last month after he was unable to secure enough votes to continue at House speaker. Rep. Emanuel “Chris” Welch, a Democrat from Hillside who is seen as a Madigan loyalist, ascended to the leadership position.

In a statement, Welch thanked Madigan for his “sincere and meaningful contributions to our state.”

“Under him, we’ve had strong, sustained Democratic leadership in Springfield,” Welch said, highlighting some legislative accomplishments like legalizing same-sex marriage and abolishing the death penalty.

“Now we must build on that with a new generation of leadership focused on racial and gender equity in all dimensions, improving government transparency, and leading with the kind of conviction, compassion and cooperation expected by our constituents,” Welch’s statement continued. “I truly appreciate his contributions and I join Illinoisans across the state in wishing him well.”

Union presidents, who’ve been allied with Madigan, lauded his work. Chicago Federation of Labor President Bob Reiter called the former speaker a “steadfast, dedicated, and courageous champion of workers and their families in Illinois for a generation.” Leaders of the Illinois AFL-CIO said Madigan “knew better than anyone that leading the Legislature means keenly understanding each legislative district and how best to support legislators representing their constituents back home and in Springfield.”

The former speaker’s fall from leadership came after federal prosecutors accused leaders at utility giant ComEd of bribing associates of Madigan in exchange for his organization’s help in passing favorable legislation.

Those accusations, which were laid out in a July indictment, loosened Madigan’s grip on the speaker’s gavel and caused some legislators, including Gov. J.B. Pritzker, to call for him to resign if the allegations were true.

Nineteen reps, some pointing to the ComEd allegations, said they would not vote for him to remain as speaker, effectively denying Madigan the votes needed to remain in power.

Madigan has not been charged with any crime and denies wrongdoing, but his confidant Michael McClain and three other members of his inner circle were indicted in November for an alleged bribery scheme designed to influence him.

A spokeswoman said Madigan will remain the chair of the Illinois Democratic Party. His resignation will kick off an appointment process that could see him personally pick his successor. As a member of the Cook County Democratic Party, Madigan has the largest share of the weighted vote that will decide who replaces him in the House.

This is a developing story. Check back for updates.