Ruth Richardson, the top regional leader of Planned Parenthood, announced late Friday that she was resigning her seat in the Minnesota Legislature effective immediately.

Richardson, a Mendota Heights DFLer elected to the House in 2019, did not provide a reason for her departure, nor did she respond to calls and emails. She became CEO of Planned Parenthood North Central States last year.

In a post at 6:21 p.m. on X, the site formerly known as Twitter, Richardson called serving in the Legislature “the honor of a lifetime.” She went on: “Legislative service is for a season and my season of service is ending effective immediately.”

Secretary of State Steve Simon said Saturday that Gov. Tim Walz will set the date of a special election to replace Richardson. The only requirement is that someone is in the seat by the start of the 2024 legislative session on Feb. 12, Simon said.

“We have already been in touch with members of the governor’s legal team, and will be briefing them on their options after the holiday,” Simon said. He expects to know more next week.

In November 2022, Richardson was re-elected to a two-year term. Two months before that, she was named to the Planned Parenthood post. She is the first Black woman to hold the CEO position, taking the job with the state’s largest abortion provider in the pivotal months after the U.S. Supreme Court overturned Roe v. Wade.

At the time of her hiring, Richardson faced questions about her ability to balance the two demanding jobs; she said she could do it. Both Richardson and Planned Parenthood leaders said she would not be involved in political work or lobbying while in the Legislature.

But in recent months, Richardson ran into trouble with labor, a key DFL ally. The Service Employees International Union (SEIU) rescinded its endorsement of her, saying she had overseen a union busting campaign at Planned Parenthood, the Minnesota Reformer reported in July.

Some 435 Planned Parenthood workers unionized in 2022 at the nonprofit health care organization. Two of the union leaders were fired and the rest were disciplined, the Reformer reported. Workers protested at the Capitol outside the House chamber in April, demanding Richardson meet them.

The workers alleged the firings were retaliation and filed charges with federal labor regulators. Richardson did not comment, but Planned Parenthood issued a statement saying the allegations of union-busting were unfounded.

As a DFL member of the House, Richardson represented Inver Grove Heights, Sunfish Lake and portions of Eagan and Mendota Heights. Before taking the CEO job at Planned Parenthood, she was the chief executive at Wayside Recovery Center, a nonprofit based in St. Louis Park that provides mental health and substance abuse support.

Until Richardson’s announcement, the DFL controlled the House 70-64. With her resignation, the DFL caucus drops to 69.

Richardson was first elected in 2018 when she defeated one-term Republican representative Regina Barr. In the last two elections, Richardson easily defeated Republican challenger Cynthia Lonnquist.

House Speaker Melissa Hortman, DFL-Brooklyn Park, did not immediately provide comment about the departure.