The U.S. Senate plans to hold hearings next month on telecommunications giant AT&T's plans to buy Time Warner for $85.4 billion in cash and stock.
Republican Mike Lee and Democrat Amy Klobuchar of the antitrust subcommittee say the merger of the two communication behemoths would potentially raise significant antitrust issues.
Both senators say they "have carefully examined consolidation in the cable and video content industries to ensure that it does not harm consumers."
The merger has also become an issue in the presidential campaign.
A spokesman for Democratic candidate Hillary Clinton said there are a lot of questions and concerns and a lot more information on the merger needs to come out.
Republican nominee Donald Trump said Saturday he would block the deal if he is elected.
"It's too much concentration of power in the hands of too few," he said. Trump has accused big media of plotting with Clinton to steal the election from him.
But there is nothing a President Clinton or a President Trump could do to stop the merger. It is eventually up to the Justice Department to determine if the deal breaks antitrust laws.
AT&T is one of the world's pioneering telecommunications companies, whose roots go back to the invention of the telephone in 1879.
Time-Warner is another communications and entertainment giant whose holdings include HBO, CNN and the Warner Brothers film studio. Those were separate publishing and entertainment corporations before merging in 1990.
This is a perfect match of two companies with complementary strengths," AT&T Chairman and CEO Randall Stephens said in a statement that went on to say that "the new company would deliver what customers want."
Time Warner Chairman and CEO Jeff Bewkes said, "Combining with AT&T dramatically accelerates our ability to deliver our great brands and premium content to consumers on a multiplatform basis and to capitalize on the tremendous opportunities created by the growing demand for video content."
The Boards of directors of both companies have already approved the merger. Time-Warner shareholders also must vote on the deal.