After lawmakers collected hundreds of hours of interviews and obtained more than 1.3 million documents about Amazon, Apple, Facebook and Google, their chief executives will testify before Congress on Wednesday to defend their powerful businesses from the hammer of government.

The captains of the New Gilded Age — Jeff Bezos of Amazon, Tim Cook of Apple, Mark Zuckerberg of Facebook and Sundar Pichai of Google — will appear together before Congress for the first time to justify their business practices.

Members of the House judiciary’s antitrust subcommittee have investigated the Internet giants for more than a year on accusations that they stifled rivals and harmed consumers.

The hearing is the government’s most aggressive show against tech power since the pursuit to break up Microsoft two decades ago. It is set to be a bizarre spectacle, with four men who run companies worth a total of around $4.85 trillion — and who include two of the world’s richest individuals — primed to argue that their businesses are not really that powerful after all.

And it will be a first in another way: Zuckerberg, Pichai, Bezos and Cook will all be testifying via videoconference, rather than rising side-by-side for a swearing-in at a witness table in Washington. Perhaps appropriately, their reckoning will be broadcast online.

“It has the feeling of tech’s Big Tobacco moment,” said Gigi Sohn, a former senior adviser at the Federal Communications Commission and a fellow at Georgetown University’s law school, referring to the 1994 congressional appearance of top executives of the seven largest American tobacco companies, who said they did not believe that cigarettes were addictive.

The hearing, which caps a 13-month investigation by the House subcommittee, will be closely watched for clues that could advance other antitrust cases against the companies. The Federal Trade Commission, for one, is preparing to depose Zuckerberg and other Facebook executives in its 13-month probe of the social network. The justice department may soon unveil a case against Google. And an investigation into Apple by state attorneys general also appears to be advancing.

As a result, preparations for the hearing have been frenetic — even with the event postponed by a few days this week to accommodate the commemoration of Representative John Lewis — as tech lobbyists jockeyed behind the scenes to influence the types of questions that lawmakers might ask.

At the hearing, which starts at noon on Wednesday, the 15 members of the antitrust subcommittee will have five minutes for each question. Representative David Cicilline, Democrat of Rhode Island and the chairman of the subcommittee, will control the number of rounds of questioning, potentially stretching questioning into the evening.

The length of the hearing may also be prolonged since the antitrust issues facing Apple, Facebook, Google and Amazon are complex and vastly different.

Amazon is accused of abusing its role as both a retailer and a platform hosting third-party sellers on its marketplace. Apple has been accused of unfairly using its clout over its App Store to block rivals and to force apps to pay high commissions.

Rivals have said Facebook has a monopoly in social networking. Alphabet, the parent company of Google, is dealing with multiple antitrust allegations because of Google’s dominance in online advertising, search and smartphone software.

New York Times News Service