T-Mobile US Inc.'s proposed $26.5 billion purchase of Sprint Corp. came under congressional scrutiny for the second time in as many months, with Democrats warning that the merger between two of the nation's top four carriers could lead to higher prices for consumers.

"I'm deeply skeptical that consolidation is the path forward" to lower prices and more competition, said Rep. David Cicilline, of Rhode Island, the Democratic chairman of the House antitrust subcommittee, as he opened the panel's hearing Tuesday.

T-Mobile Chief Executive Officer John Legere and Sprint Executive Chairman Marcelo Claure appeared before the panel to defend their bid to combine the third- and fourth-largest U.S. wireless carriers. The companies say that together they could build an advanced 5G network, and form a stronger competitor to mobile leaders AT&T Inc. and Verizon Communications Inc.