Nevada Sen. John Ensign (R) announced Thursday he will resign his seat on May 3, due to a Senate ethics committee investigation over his extramarital affair with a former campaign aide.

"It is with tremendous sadness that I officially hand over the Senate seat that I have held for eleven years,” said Ensign. "The turbulence of these last few years is greatly surpassed by the incredible privilege that I feel to have been entrusted to serve the people of Nevada. I can honestly say that being a United States Senator has been the honor of my life."

The senator, who has served since January 2001, was a rising star in the party when he admitted to an extramarital affair in 2009. His parents reportedly wrote a $96,000 check to his former mistress and her family, leading to an investigation by the Federal Election Commission, which was later dismissed.

It was later revealed that Ensign may have violated Senate ethics rules by arranging for his former mistress's husband to take a job as a lobbyist with a Nevada consulting firm in an attempt to hush the matter up.

Ensign, 51, a staunch conservative with a record of strong family-values stances, had vowed to remain in office after describing the affair as "absolutely the worst thing I've ever done in my life" at a news conference.

He said he and his wife, Darlene, had reconciled thanks to marital counseling and that his marriage is "stronger than ever."

“While I stand behind my firm belief that I have not violated any law, rule, or standard of conduct of the Senate, and I have fought to prove this publicly, I will not continue to subject my family, my constituents, or the Senate to any further rounds of investigation, depositions, drawn out proceedings, or especially public hearings," Ensign said. "For my family and me, this continued personal cost is simply too great."

"To the people of Nevada, I humbly say thank you for what you have given to me through the years," he added. "To my family, thank you for the support and love that you have shown me. To my staff, thank you for coming on this incredible journey with me and for standing by me despite the obstacles."

With prior reporting by Sahil Kapur.