An AT&T logo is pictured in Pasadena, California, U.S., January 24, 2018. REUTERS/Mario Anzuoni

WASHINGTON (Reuters) - Four Democrats in the House of Representatives wrote the Justice Department on Thursday to request documents related to its decision to file a lawsuit to stop AT&T T.N from buying Time Warner TWX.N.

“We are deeply concerned by reports of inappropriate interference by the White House,” said the letter which was signed by Representatives Jerrold Nadler, Elijah Cummings, David Cicilline and Gerald Connolly.

U.S. President Donald Trump attacked the deal while on the campaign trail in 2016. Trump has also criticized Time Warner’s CNN news network and, in November, reiterated his opposition to the proposed transaction.

The Justice Department has said that the $85 billion deal is illegal because AT&T, if it owned movie and television show maker Time Warner, would have the ability and incentive to raise prices that it charges cable, satellite and streaming rivals for Time Warner’s content. A trial is set for next month.