MINNEAPOLIS (WCCO/AP) — Following weeks of accusations made against him, Sen. Al Franken has announced he is stepping down at the end of the year.

“I am proud that during my time the Senate I have used my power to be a champion of women and that I have earned a reputation as someone who respects the women I work alongside every day. I know there’s been a very different picture of me painted over the last few weeks, but I know who I really am,” Franken said on the U.S. Senate floor Thursday morning.

“Serving in the United States Senate has been a great honor of my life. I know in my heart that nothing I have done as a Senator, nothing, has brought this honor on this institution and I am confident that the ethics committee would agree. Nevertheless today I am announcing that in the coming weeks I will be resigning as a member of the United States Senate,” Franken added. “Even today, on the worst political day of my life, I feel like it’s all been worth it.”

On Wednesday, more than a dozen Democrats in the U.S. Senate all called on Franken to resign, including neighboring Wisconsin’s Sen. Tammy Baldwin.

Sen. Kirsten Gillibrand wrote on Facebook that while Franken is entitled to have the Ethics Committee conclude its review, “I believe it would be better for our country if he sent a clear message that any kind of mistreatment of women in our society isn’t acceptable by stepping aside to let someone else serve.”

Sens. Mazie Hirono of Hawaii, Maggie Hassan of New Hampshire, Patty Murray of Washington state and Claire McCaskill of Missouri also joined those pressing for Franken to quit, among others.

“I of all people am aware that there is some irony that I am leaving while a man who has bragged on tape that his history of sexual assault sits in the Oval Office and a man who has repeatedly preyed on young girls campaigns for the Senate with the full support of his party,” Franken said. “Over the last few weeks a number of women have come forward to talk about how they felt my actions affected them. I was shocked, I was upset. But in responding to their claims, I also wanted to be respectful of that broader conversation, because all women deserve to be heard and their experiences taken seriously. I think that was the right thing to do. I also think it gave some people the false impression that I was admitting to doing things that in fact I hadn’t done. Some of the allegations against me are simply not true, others I remember very differently.”

Sources tell WCCO’s Pat Kessler that Minnesota’s lieutenant governor, Tina Smith, leads the list of potential Franken replacements until Minnesotans elect a replacement in 2018. That replacement would serve until 2020, when Franken was due for re-election.

Earlier on Wednesday, another woman came forward in Politico with allegations against Franken. The publication is withholding the name of the former congressional staffer who says Franken tried to kiss her in 2006.

Franken released a statement almost in conjunction with the release of the report saying he categorically denies this incident happened, which was a bit of a change from what he has said in the other instances.

This latest accuser was a Democratic congress member’s staffer in 2006 when she says Franken tried to kiss her when the two were alone and when she ducked he said “it’s my right as an entertainer.”

“I don’t want to be in the position of deciding whether to tell this story but I’m not the person who put me in that position. He did that,” the woman said. “I think for this moment in time to lead to meaningful change there has to be more than ‘I’m ashamed but I remember things differently’ accounting.”

Franken responded: “This allegation is categorically not true and the idea that I would claim this as my right as an entertainer is preposterous. I look forward to fully cooperating with the ongoing ethics committee investigation.”

The accusations began with Leeann Tweeden, who in mid-November said Franken groped her while she slept and forcibly kissed her during a skit rehearsal. Since then, women have come forward alleging Franken inappropriately touched them on the back side during photos.

When WCCO’s Esme Murphy sat down with Franken late last month in Washington, before this latest allegation, Franken repeatedly said he did not recall the instances the way his accusers did but that he was sorry.

“I understand I am going to have to do everything I can going forward to be enormously sensitive, I apologize to these women,” Franken said.

Franken earlier said he agreed to cooperate with a Senate Ethics Committee investigation into his behavior. Last week, Senate officials confirmed that investigation was already underway.

Also this week, Time Magazine honored all who have broken their silence recently about being sexually assaulted or harassed in the past, calling “the silence breakers” their Person of the Year.

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)