By Dan Merica, CNN

Washington (CNN) – American Atheists, an outspoken organization that advocates for atheists nationwide, will have a booth at the 2014 Conservative Political Action Conference.

The atheist institution, which is well known for its controversial billboards and media campaigns, informed CNN of its inclusion on Monday night, and a representative from CPAC confirmed that the group will have a booth at the annual national gathering of conservative leaders and activists in March. American Atheists hopes to use the forum to tap into the conservative movement and bring conservative atheists “out of the closet.”

“Just as there are many closeted atheists in the church pews, I am extremely confident that there are many closeted atheists in the ranks of conservatives," said David Silverman, president of American Atheists.

Silverman said coming to CPAC will be “the first step of many” in reaching out to Republicans.

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“It is really a serious outreach effort, and I am very pleased to be embarking on it,” Silverman said.

The group’s inclusion is believed to be the first time that atheists have been involved in the conservative political gathering that has long been associated with Christian conservatives.

The Conservative Political Action Committee, the largest and oldest gathering of conservatives, is run by the American Conservative Union and will be held at the Gaylord National Resort & Convention Center in National Harbor in Maryland from March 6 to 8. Last year, the event brought together thousands of activists to listen to dozens of Republican leaders speak about everything from economics and foreign policy to social issues. The event has long been considered a required stop for Republican presidential hopefuls.

Meghan Snyder, spokeswoman for CPAC, said American Atheists were included in the confab because “conservatives have always stood for freedom of religion and freedom of expression.”

“The folks we have been working with stand for many of the same liberty-oriented policies and principles we stand for,” Snyder said in an e-mail to CNN.

Tony Perkins, president of the Christian conservative think-tank Family Research Council, doesn't see it that way. In an email to CNN, a rankled Perkins wrote that the atheist group does "not seek to add their voice to the chorus of freedom."

"CPAC's mission is to be an umbrella for conservative organizations that advance liberty, traditional values and our national defense," said Perkins, who spokes at CPAC in 2012. "Does the American Conservative Union really think the liberties and values they seek to preserve can be maintained when they partner with individuals and organizations that are undermining the understanding that our liberties come from God? Thomas Jefferson warned against such nonsense."

The social conservative leader added: "If this is where the ACU is headed, they will have to pack up and put away the 'C' in CPAC!"

In explaining why the group decided to join CPAC, Silverman cited a 2012 Pew Research study that found 20% of self-identified conservatives consider themselves religiously unaffiliated. While that does not mean they are atheists, Silverman believes learning more about atheism will make it more likely conservatives will choose to identify with those who believe there is no God.

“Conservative isn’t a synonym for religious,” Silverman said. “I am not worried about making the Christian right angry. The Christian right should be angry that we are going in to enlighten conservatives. The Christian right should be threatened by us.”

American Atheists paid $3,000 for booth 439 in the event’s exhibition hall. Their booth will be right next to the Republican National Committee's booth, according to the room map.

American Atheists is known as the in-your-face contingent in the world of atheist activists, and the group’s members pride themselves as being the “Marines" of the atheist movement.

The group has long targeted Republican lawmakers, although Silverman considers the organization nonpartisan.

In 2013, American Atheists launched a billboard campaign against three Republican politicians: former vice presidential candidate Sarah Palin, former House Speaker Newt Gingrich and former Pennsylvania Sen. Rick Santorum. All three Republicans have spoken at CPAC in the past.

In one billboard, Santorum is pictured to the left of a quote attributed to him. “Our civil laws have to comport with a higher law. God’s law,” the quote reads. Underneath the graphic is a tagline: "GO GODLESS INSTEAD."

The group has also prided itself on trying to reach into religious communities and bring people out of the closet. In 2012, American Atheists asked Jews and Muslims to come out of the closet in a targeted billboard campaign.

In addition to Silverman, Amanda Knief, American Atheist’s managing director, and Dave Muscato, the group’s spokesman, will attend CPAC. Silverman said they will be prepared to respond to questions from conference attendees.

UPDATE: CPAC reversed their decision and will not allow American Atheists to have an exhibition booth at the conservative conference.