The Federal Trade Commission could force Facebook to back out of its plans to integrate its family of apps, including Instagram, Messenger, and WhatsApp, The Wall Street Journal reported on Thursday. 

According to the Journal’s exclusive, officials have grown fearful in recent months that any moves to further tie Facebook’s products together could make it more difficult for agencies like the FTC or law enforcement to break the company up in any future antitrust case. Sources told the Journal that any FTC action would seek to block the integration over competition concerns. In order to seek such an injunction, the FTC would need at least three of its five commissioners to vote in favor of the move. 

The FTC declined to comment. Facebook did not immediately respond to a request for comment. 

Facebook first announced that it would begin to stitch together the underlying infrastructure of its messaging apps in March.

“People want to be able to choose which service they use to communicate with people,” wrote CEO Mark Zuckerberg in a blog post announcing the decision. “We want to give people a choice so they can reach their friends across these networks from whichever app they prefer.”

Facebook first disclosed that it was under investigation by the FTC for potential antitrust violations last July. At this point, it’s not clear whether the agency will take action as a result of that probe. Any injunction to keep Facebook from making its platforms interoperable could be seen as setting the agency up for more extensive antitrust action in the future. The Journal reported that an injunction could come as soon as January.

The Justice Department also has the authority to enforce antitrust law and is currently probing the tech industry for anti-competitive behavior. At a conference earlier this week, Attorney General William Barr said that he hopes to have the Department of Justice’s review completed by the end of the year.