New Democrat MP Judy Wasylycia-Leis is leaving federal politics.
Effective May 1, Ms. Wasylycia-Leis will resign the Winnipeg North seat she has held since 1997.
A former culture minister in the Manitoba provincial government of Howard Pawley, Wasylycia-Leis says it's the right time to move on.
She says she wants to spend time with her family before making an announcement about her future.
Ms. Wasylycia-Leis, 58, represented the Winnipeg seat once held by legendary New Democrat MP Stanley Knowles.
She served as caucus chair, finance critic and health critic, winning support for some key legislation, including fetal alcohol syndrome warning labels on alcohol bottles, prohibitions on candy-flavoured cigarillos and improved toy safety standards.
NDP Leader Jack Layton said Ms. Wasylycia-Leis has been one of the country's most determined and effective health-care advocates.
"Judy has been a warrior on this issue in our caucus," Mr. Layton said in a statement, echoing praise from Shirley Douglas, daughter of medicare founder Tommy Douglas, who once called her "Canada's medicare warrior."
"She has been a much-valued member of our caucus," Mr. Layton said. "She will be a hard act to follow.
"I wish her well in her next adventure. I know she will always be a loyal member of the New Democrat family. We'll miss her cheerful can-do attitude."