(CNN) – The nation's largest tea party political action committee, the Tea Party Express, is calling on Rep. Todd Akin to step down as Missouri's Republican nominee for a Senate seat on Monday following controversial comments the congressman made about rape.
Answering a question about whether he thought abortion should be legal in cases of rape, Akin said in an interview Sunday that in instances of "legitimate rape" the female body has ways of stopping a potential pregnancy. Video of the interview was posted online by the liberal super PAC American Bridge.
– Follow the Ticker on Twitter: @PoliticalTicker
– Check out the CNN Electoral Map and Calculator and game out your own strategy for November.
Tea Party Express Chairman Amy Kremer said in a statement released Monday that Akin's remarks were "unfortunate and inappropriate."
"It is critical that we defeat Senator Claire McCaskill in November, but it will be too difficult to achieve with Todd Akin as the conservative alternative," said Kremer. "He should step down and give conservatives a chance at taking back the Senate in November."
"One of the lessons we learned in 2010 is that we need candidates who are not only conservative, but are capable of putting together a strong campaign against liberal opponents," said Kremer, calling Akin's comment a 'Bidenism' in an apparent reference to Vice President Joe Biden's recent 'chains' gaffe at a campaign stop in Virginia.
In a radio interview Monday, Akin apologized for the comments.
"I made that statement in error. Let me be clear. Rape is never legitimate. It's an evil act, and it's committed by violent predators," the Republican congressman said on Mike Huckabee's radio show.
The Tea Party Express endorsed Akin's rival, former state treasurer Sarah Steelman, in Missouri's GOP primary. Steelman, who was defeated by Akin in the August 7 contest, also grabbed the coveted conservative endorsement of former Alaska Gov. Sarah Palin.
Notwithstanding calls for the congressman to drop out, Akin is set to go up against incumbent Democratic Sen. Claire McCaskill in November's election.
The Tea Party Express's push for Akin to step down comes in a wave of conservative backlash over the congressman's comments that critics say could jeopardize the Republican effort to gain control of the Senate in November.
Currently, the Senate is controlled by the Democratic Party by a 53-47 margin but they are defending 23 (21 Democrats and two independents who caucus with the party) of the 33 seats up for grabs in November.
Tea Party Nation, the group that organized the first National Tea Party Convention in 2010, also urged Akin to step down. The group's founder, Judson Phillips, encouraged the congressman to step aside following what the group calls "amazingly stupid comments about rape."
"Control of the Senate could come down to this race and Todd Akin, whose ego is much bigger than his brain, may cost the Republican's control of the Senate," said Phillips in a press release Monday.
Meanwhile, some socially conservative groups have defended Akin in recent hours. Top officials from the Family Research Council stood by Akin, saying he was simply caught in a "gotcha politics" moment. Furthermore, the Missouri Right to Life, a group with which Akin once served as a board member, came to the congressman's defense.
"Missouri Right to Life supports Congressman Akin's defense of the life of an innocent unborn child conceived by rape. We also support his statement of compassion and support for victims of sexual assault," said Pam Fichter, president of the group's PAC, in a statement.
CNN's Paul Steinhauser, Dana Davidsen and Ashley Killough contributed to this report.