Interim Conservative leader Rona Ambrose is expected to announce Tuesday that she will resign her seat in the House of Commons this summer.
The longtime Alberta MP has been serving as the temporary head of the party since the fall of 2015.
Sources say she intends to outline her plans in a farewell breakfast speech Tuesday ahead of a planned tribute in the Commons.
The Conservative party is currently in the process of picking a new leader, with the winner to be announced May 27.
Ambrose had always intended to stay serving as an MP during the transition period, though she is already moving out of the Official Opposition leader's residence of Stornoway.
She was first elected an MP in 2004 and served in several cabinet positions under previous Conservative leader Stephen Harper.