Senator Don Meredith is resigning from the Red Chamber before his colleagues can vote on whether to expel him for having a sexual relationship with a teenage girl.
But it remains unclear whether an investigation into allegations of workplace harassment against Mr. Meredith, a married 52-year-old Pentecostal pastor, will continue once he leaves the chamber.
He is also set to keep his federal pension worth approximately $25,000 a year.
In a statement published Tuesday on Senate letterhead, Mr. Meredith said he has "decided to move forward with my life" with support of his wife and children.
"I am acutely aware that the Upper Chamber is more important than my moral failings," Mr. Meredith wrote.
"The path of expulsion being considered by my colleagues will have major implications for the Senate of Canada. This is a constitutional fight in which I will not engage."
Although Mr. Meredith did not mention the word resignation, his lawyer, Bill Trudell, said he sent a letter to the Governor-General about his decision to resign. Rideau Hall says it has been informed of the letter but has not yet received it.
Most senators were in the chamber when they heard the news and many said Mr. Meredith will not be missed.
"He didn't behave honourably, and he didn't resign honourably," Conservative Senator Denise Batters told reporters. "Good riddance."
Mr. Meredith's decision comes as the Senate was set to debate and vote on a report from the ethics and conflict-of-interest committee, which recommended that Mr. Meredith be kicked out of the Senate for his sexual relationship with a teenage girl that began when she was 16.
If he were expelled, the outcome would have been unprecedented. The Senate's law clerk and parliamentary counsel determined that, like Britain's House of Commons, the Senate has the authority to expel one of its members. Mr. Meredith and his lawyer had argued at the Senate ethics committee for a one or two-year suspension without pay.
Mr. Meredith was appointed to the Senate by former prime minister Stephen Harper in December, 2010, and became eligible for his pension after six years. It was unclear whether he would have kept the pension had he been expelled, and the Treasury Board was said to be examining the scenario prior to his resignation.
Mr. Meredith is also facing two other investigations into allegations of workplace harassment and another for including a business associate on a delegation to the Caribbean. Several senators said they hoped the investigations would continue after Mr. Meredith departs. "It's important for the employees, it's important for the image of the Senate," Conservative Senator Pierre-Hugues Boisvenu said.
According to the Senate ethics and conflict-of-interest code, when a senator ceases to be a senator, inquiries are permanently suspended unless the ethics committee decides otherwise. Newly appointed independent Senator Marilou McPhedran, a human-rights lawyer, said she intends to file a notice of inquiry in the Senate to examine how the institution "upholds the public trust."
The committee's recommendations followed an explosive investigation from Senate ethics officer Lyse Ricard into Mr. Meredith's relationship with a teenage girl, called only Ms. M., which began when she was 16 and lasted for two years.
Ms. Ricard's report found that Mr. Meredith, who calls himself a "devoted champion of youth empowerment," breached two sections of the ethics code in his relationship with the teenager. Although Mr. Meredith denied having sex with Ms. M. before she turned 18, Ms. Ricard determined that Mr. Meredith had intercourse with the teenager once when she was 17 and twice when she was 18.
Mr. Meredith told the Senate ethics officer that what happened with the young woman is a personal matter and is unconnected to his duties as a senator. He apologized and asked his colleagues for forgiveness. Ms. Ricard found that Mr. Meredith's contact with the woman was "substantially intermingled" with his role as a senator, and that he drew on the weight and prestige of his role as a senator to "lure" her into a relationship. Ms. Ricard also found Mr. Meredith was not credible in his testimony.