AUGUSTA (AP) — Maine Health and Human Services Commissioner Mary Mayhew, who led sweeping welfare reform efforts since taking on the role in 2011, said Wednesday she is leaving Gov. Paul LePage’s administration by the end of this week.

LePage, a Republican, said his office will announce an acting commissioner later this week. He praised Mayhew, saying she had “the fortitude and the competence to finally bring accountability and fiscal responsibility to Maine’s formerly out-of-control welfare system.”

The reason for Mayhew’s departure is unclear as are her next steps, though she has been mentioned as a potential gubernatorial candidate in 2018. Mayhew has long received criticism from anti-poverty groups and Democrats. Maine Democratic Party Chairman Phil Bartlett questioned why she’s “walking out on her job in the middle of a critical budget negotiation.”

Mayhew declined to take questions at a news conference Wednesday, and her office didn’t respond to additional request for comment. Mayhew said she will continue to serve as commissioner until Friday.

“When I arrived in this position, we were hemorrhaging red ink,” Mayhew said. “You cannot plan when you are in a constant state of financial crisis.”

LePage said Mayhew handled pushback from special interest groups, liberal legislators and the media with “grit and grace” as she controlled spending and created “pathways to employment and self-sufficiency.”

“Maine taxpayers, as well as those who have found success moving from welfare to work, should thank Mary for a job well done,” LePage said.

Mayhew was a Democrat when she was appointed in 2011; she’s now a Republican.

In recent months, Democrats have said the Department of Health and Human Services failed to spend millions of dollars in federal funds meant for the needy. The department has since said it has a plan to use such funds.

Mayhew’s efforts to increase work requirements and penalties for public assistance programs and Medicaid also have drawn scrutiny from Democrats. Democratic Rep. Patricia Hymanson said the department under Mayhew “operated under the belief that people can be punished out of poverty.”

Bartlett called the resignation announcement “Mayhew’s first step toward running for Governor,” and said she is “putting her personal political ambitions over the well-being of Maine’s people.”

“She is the poster child for an administration that throws out buzzwords like ‘accountability’ and ‘fiscal responsibility,’ when they really mean throwing the working Mainers they promised to help under the bus,” Bartlett said.