Executives representing AT&T and DirecTV were grilled by members of Congress on Tuesday when they proposed a $48.5 billion merger that Democratic critics and public interest groups fear will result in higher costs and less competition.

During hearings in both the House of Representatives and the Senate, the chief executives of the No. 2 wireless carrier and the largest U.S. satellite TV service provider argued that their multi-billion deal would be good for competition and pressure cable companies to lower prices.

"Econometric analysis confirms that by making us more competitive, the merger will put downward pricing pressure on cable products -- cable bundles, cable video and cable broadband," said AT&T CEO Randall Stephenson to antitrust subcommittees in the House and Senate, according to the New York Times.

However, their argument crumbled when Democratic Sen. Richard Blumenthal asked whether AT&T would pass along to consumers all the savings the company expects to realize from the merger.

"No sir, I cannot commit to that," responded Stephenson, adding that he hoped the merger would result in slower price increases for consumers.

"One would have to believe in the market and the market pressures, and that market pressures will compete margins away and cost savings will find their way into prices," he said.

Sen. Blumenthal also questioned whether AT&T would commit to offering either 75 or 50 percent of the savings to consumers, but Stephenson replied, not right here and right now. "I can't even tell what the prices of these services will be six months from now, much less three years from now," he stated.

The companies say their merger would allow them to better compete with cable companies and expand Internet service to around 13 million customers living in rural areas.

DirecTV CEO Michael White added that he expected customers to see better value bundles.

However, representatives of content producers and smaller cable operators denounced the deal, alleging the combined company would have too much power over the creation, distribution and costs of programming, reports Reuters.

Rep. Spencer Bachus, the Alabama Republican who oversees the House antitrust subcommittee, said that he favored the current deal, but admitted that consolidation in the telecommunications industry does raise "issues of market power and the abuse of dominant competitive positions."

Nonetheless, the companies have told regulators that they should approve the merger because AT&T and DirecTV complement each other more than they compete.

"By combining complementary assets and products, we will be able to offer new service at a better value," White said. "We will help consumers watch the video they want, when they want it, where they want it, on the devices of their choice."

However, John Bergmayer, a senior staff lawyer at Public Knowledge, doesn't buy that arguement.

"This proposed deal fails the antitrust test, it fails the public interest test, and it raises many concerns," Bergmayer said. "It's hard to accept AT&T's claims that buying a direct rival can be good for competition."

Consumer advocates are also concerned that consolidation would lead to less choices and higher prices for consumers.

"I am very, very skeptical as a senator, not just as a consumer," said Sen. Blumenthal.