When Democrats take control of the U.S. House they plan to investigate the Trump administration's attempt to block AT&T Inc. from acquiring Time Warner, and whether officials sought to punish Amazon.com Inc. by prodding the U.S. Post Office to hike shipping prices for the world's largest e-commerce company, a senior Democrat and a congressional aide said on Sunday.

Speaking to online publication Axios, Rep. Adam Schiff, who is expected to be the incoming chairman of the House Intelligence Committee, said Democrats will review if Trump used the powers of the federal government to punish the companies.

Rep. Elijah Cummings, the likely incoming chairman of the House Oversight and Government Reform Committee, said the committee "may want to look into" if the White House retaliated against Amazon and AT&T.