Facebook announced Thursday that it will create an independent governing body to moderate content on the platform, marking a significant change in how the company handles editorial decisions.

The body, first discussed on a call with reporters on Thursday, will aim to “uphold the principle of giving people a voice while also recognizing the reality of keeping people safe” and decide which content is allowed on the platform under the company’s terms of service, according to a blog post from Facebook CEO Mark Zuckerberg.

The board will launch in the beginning of 2019 after the company decides who will be a part of the new governing body and the process through which they will be petitioned, Zuckerberg wrote.

“Just as our board of directors is accountable to our shareholders, this body would be focused only on our community,” Zuckerberg wrote.

Facebook has recently begun to take a more active role in policing content and banned some pages, including those of far-right website Infowars and its founder, Alex Jones. Websites like Reddit and Wikipedia have operated for years on volunteer outside moderator systems that debate, set rules and remove unacceptable or dangerous content. It is not clear if the governing body would be comprised of volunteers or paid employees.

Zuckerberg announced the governing body in a phone call that quickly turned away from the company’s announcement and toward a lengthy report from The New York Times that revealed the company paid Definers Public Affairs, a Republican opposition research firm, to discredit Facebook opponents — including linking a group to liberal philanthropist George Soros.

During the call with reporters, Zuckerberg weathered a barrage of questions about the company’s role in the lobbying campaign against activist groups. Zuckerberg said he was unaware of Facebook’s relationship with the lobbying firm until it was outlined in the Times on Wednesday.

Zuckerberg did not say who was responsible for the relationship with Definers but said that the company will re-evaluate the hiring of lobbying firms in Washington.

"I understand that a lot of D.C.-type firms might do this kind of work,” said Zuckerberg. “When I learned about it I decided that we don’t want to be doing it."

Zuckerberg also offered a strong defense of Sheryl Sandberg, the chief operating officer of Facebook, calling her a “great partner." He said she was also unaware of Definers’ role working with Facebook until Wednesday. The Times detailed how Sandberg had led the company's efforts to push back against critics.

“She learned about this the same time I did,” Zuckerberg said on the call.

Four Democratic senators on Thursday said they had sent a letter to the Justice Department asking prosecutors to expand an investigation into Facebook to include whether the company hid information or retaliated against people seeking to regulate it.

Facebook's actions "may have implications for securities and campaign finance law" if the company didn't properly disclose what it did, Sen. Amy Klobuchar, D-Minn., and three others wrote.

Zuckerberg said an internal probe on the Definers controversy will be headed up by Facebook's vice president of global affairs, Nick Clegg, the former U.K. deputy prime minister who recently joined the company.

Facebook also released an “enforcement report” on Thursday outlining the amount of content and number of accounts pulled down for content violations. Some reporters on the call remarked on what appeared to be a lack of enforcement of what was considered “bullying” — about 2.1 million incidents from July to September — since Facebook announced its new anti-bullying rules in March.

By contrast, Facebook took action on 754 million fake accounts — with the company taking action on 99.6 percent of all cases before being notified by users, the company said.