Dozens of prominent conservative leaders have issued a joint statement regarding censorship and suppression of conservative speech by tech giants Facebook, Twitter, Google and YouTube after right-leaning users have complained of bias for years.

“Social media censorship and online restriction of conservatives and their organizations have reached a crisis level,” the statement begins. “Conservative leaders now have banded together to call for equal treatment on tech and social media.”

The participants have called for the tech giants to address the key areas of complaint including lack of transparency when removing content and deleting accounts and the imbalance of liberal content advisers like the Southern Poverty Law Center.

The conservative leaders want the tech companies to adopt four key principles to ensure that conservatives receive equal treatment, according to the Media Research Center. The four principles are providing transparency, providing clarity on what is considered hate speech, offering “equal footing” to conservatives and a call for tech companies to mirror the First Amendment.

“Social media companies must address these complaints if they wish to have any credibility with the conservative movement and its tens of millions of supporters,” the statement says.

The joint statement comes amid news that Facebook is conducting a civil rights audit and looking into potential bias against conservative voices by bringing in two outside experts to probe its practices. The new efforts, first reported by Axios, come amid growing fallout from allegations that the tech platform discriminates against minority groups and censors conservatives.

According to Axios, the civil rights audit will be led by Laura Murphy, a national civil liberties and civil rights leader who serves as director of the American Civil Liberties Union’s Washington Legislative Office.

The statement’s 63 signees include Media Research Center President Brent Bozell, former Attorney General Edwin Meese, Citizens United President Dave Bossie, Weyrich Lunch Chairman Morton Blackwell, Senate Conservatives Fund President Ken Cuccinelli, Tea Party Patriots Citizens Fund co-founder Jenny Beth Martin, Family Research Council President Tony Perkins, LTC Allen West, Becky Norton Dunlop and Congressman Lamar Smith.

“If the social media firms engage the conservative movement with the spirit of cooperation, we will do our best to assist them,” the statement says.

Facebook is working with former Arizona Republican Sen. Jon Kyl, along with his team at D.C. law firm Covington and Burling, to probe potential anti-conservative bias. Kyl will look for alleged liberal bias on Facebook, internally and on its services, and Facebook will get feedback from conservative groups with advice on next steps to take. The Heritage Foundation, a conservative public policy organization, will meet with Facebook executives as well.

Groups on the right have said that Facebook has liberal bias for years, but recent reports allege that conservative content has been suppressed by some of its so-called “human curators.”

The far-left Southern Poverty Law Center is no stranger to controversy and bills itself as a civil rights organization that is “dedicated to fighting hate and bigotry.” However, it was accused by Politico in 2017 of “overstepping its bounds.” The controversial group recently made headlines when The Daily Caller reported that it was enlisted by YouTube to assist with policing content.

Fox News’ Christopher Carbone contributed to this report.