WASHINGTON — The political walls come closing in on Sen. Al Franken Wednesday with half of the Democrats in the Senate – led by women — called on their colleague to resign amid mounting allegations of sexual harassment.

CNN reported that he is expected to make an announcement Thursday.

Sen. Kirsten Gillibrand (D-NY) was the first of Franken’s fellow Senate Democrats to call for his resignation and was quickly followed by Mazie Hirono of Hawaii, Claire McCaskill of Missouri, Maggie Hassan of New Hampshire, Patty Murray of Washington, Kamala Harris of California and Tammy Baldwin of Wisconsin.

Male colleagues soon joined in, including Bob Casey of Pennsylvania, Joe Donnelly of Indiana and Sherrod Brown of Ohio.

“Enough is enough,” Gillibrand said at a press conference.

She first announced her decision on social media.

“While Senator 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,” Gillibrand said in a statement posted on Facebook.

“Today, I am calling on my colleague Al Franken to step aside,” Hirono agreed on Twitter. “I’ve struggled with this decision because he’s been a good Senator and I consider him a friend. But that cannot excuse his behavior and his mistreatment of women.”

Sen. Bob Casey (D-Penn.) joined as the first male colleague to ask for Franken to resign.

By early afternoon the list had grown to 24 of the 48 Democratic senators.

Rounding out the list are: Joe Donnelly of Indiana, Sherrod Brown of Ohio, Debbie Stabenow of Michigan, Michael Bennet of Colorado, Heidi Heitkamp of North Dakota, Ed Markey of Massachusetts, Dick Durbin of Illinois, Maria Cantwell of Washington, Patrick Leahy of Vermont, Dianne Feinstein of California, Martin Heinrich of New Mexico and Jeff Merkley of Oregon, Ron Wyden of Oregon, Tammy Duckworth of Illinois, Tom Carper of Delaware, Angus King of Maine and Chris Murphy of Connecticut.