AT&T has been told by the U.S. Department of Justice that it will be required to sell CNN to win approval for it to acquire Time Warner, according to a Financial Times report citing people with direct knowledge of the negotiations.

The sale of CNN is one of several demands made by the Justice Department in order to sell off the deal, according to several reports.

“It’s all about CNN,” one of the sources told the Financial Times.

As an alternative to selling CNN, AT&T has been told it could sell DirectTV, according to sources who spoke to CNBC’s Andrew Ross Sorkin.

The demand would be unusual but not unprecedented. In recent years, U.S. antitrust authorities have not acted to block so-called “vertical integration” deals such as the AT&T acquisition of Time-Warner. Instead, they have focused on “horizontal deals” that tie together competitors in the same sector.

As recently as a few weeks ago, the two companies were saying they expected to complete the merger by the end of the year. But AT&T CFO John Stephens said on Wednesday that “the closing of the deal is now uncertain.”

Donald Trump said on the campaign trail that he would block the deal. And recently several consumer advocacy groups and conservative organizations have criticized the deal.