Senator Amy Klobuchar, the top Democrat on the Senate antitrust panel, sent a letter to the U.S. Justice Department on Friday urging that it reject any effort by the White House to inject politics into merger investigations.

The letter follows a New York Times report saying that White House advisors battling television news station CNN mulled using a government review of AT&T Inc's plans to merge with CNN parent Time Warner Inc as leverage.

"Any political interference in antitrust enforcement is unacceptable. Even more concerning, in this instance, is that it appears that some advisers to the president may believe that it is appropriate for the government to use its law enforcement authority to alter or censor the press," Klobuchar wrote in a letter to Attorney General Jeff Sessions.

Both the White House and Justice Department declined comment for this story.

Klobuchar, who has herself expressed concern about the $85.4 billion megadeal, noted those concerns but added that the Justice Department's antitrust review should focus on consumer welfare rather than politics.

Klobuchar also asked Sessions to report to the Senate Judiciary Committee and the antitrust subcommittee any White House staffer or presidential adviser who had contacted the Justice Department about the merger.

President Donald Trump has not commented publicly on the deal since the election but during his campaign he said it was an example of a "power structure" that was rigged against him and "too much concentration of power in the hands of too few."