MADISON, Wis. (AP) — A powerful Republican lawmaker in the Wisconsin Legislature known for his efforts to combat the opioid abuse crisis announced Tuesday that he was resigning to pursue unspecified opportunities in the private sector, causing a surprising shakeup to the leadership of the panel that writes the state budget.

Rep. John Nygren, of Marinette, said he would resign effective Wednesday. Nygren, 56, has been in the Assembly since 2007. He has been chairman of the budget-writing Joint Finance Committee for eight years, a position that gave him tremendous say over the state's funding priorities.

Nygren's abrupt and surprise resignation means the budget committee will have two new co-chairs when the next session begins in 2021 and the panel sets about writing the next two-year state budget. Sen. Alberta Darling, who had been co-chair since 2011 and the entire eight years that Nygren was co-chair, is being replaced by Sen. Howard Marklein, of Spring Green.

Assembly Speaker Robin Vos, who will name Nygren's replacement running the committee, said he leaves a legacy of “balanced budgets, smaller government and lower taxes.”

In addition to his role shaping the state budget, Nygren was known for his effort to combat opioid abuse through a program dubbed the Heroin, Opioid Prevention and Education (HOPE) Agenda. Nygren often referenced the struggles his own daughter had with drug abuse and addiction as he lobbied to pass dozens of measures to combat substance abuse starting in 2014. The effort found broad, bipartisan support.

“His incredible work in fighting the opioid epidemic has made a difference in countless lives and will have a lasting impact on the state," Vos said.

Some of the laws co-sponsored by Nygren as part of the HOPE Agenda include creating the state's prescription drug monitoring program used by doctors and pharmacies to track patients' opioid use; allowing all emergency responders to administer Narcan, a drug that reverses the effects of a heroin overdose; and limiting immunity for people who call 911 or bring someone to an emergency room in the event of an overdose.