A prominent advocate of breaking up Big Tech firms began her first full day as the head of a key US regulatory agency on Wednesday, ramping up the potential for antitrust enforcement.

Lina Khan was sworn in Tuesday as chair of the Federal Trade Commission after the Democrat nominated by President Joe Biden was confirmed by the US Senate.

"It is a tremendous honor to have been selected by President Biden to lead the Federal Trade Commission," Khan said in a release.

"I look forward to working with my colleagues to protect the public from corporate abuse."

Biden named Khan, an associate professor of law at Columbia University's law school, to the post in March in a move suggesting an aggressive posture on antitrust enforcement.

Khan was confirmed Tuesday in a Senate vote of 69 to 28, with all the opposing votes cast by Republicans.

The FTC has authority over some mergers and antitrust policy.

"This is a big win for consumers and the public interest," said Charlotte Slaiman, of consumer advocacy group Public Knowledge.

Lina Khan previously served as counsel to the US House of Representatives subcommittee on antitrust
Lina Khan previously served as counsel to the US House of Representatives subcommittee on antitrust GETTY IMAGES NORTH AMERICA / POOL

"The strong bipartisan vote in her favor is both confirmation of her impeccable credentials and of the bipartisan interest in holding Big Tech accountable."

Khan previously served as counsel to the US House of Representatives subcommittee on antitrust, which last year released a lengthy report suggesting grounds for breaking up giants such as Facebook, Google, Amazon and Apple.

She also authored a 2017 paper entitled "Amazon's Antitrust Paradox," which outlined the growing dominance of the e-commerce and tech giant, which some say helped shift sentiment on antitrust.

Khan worked in the office of FTC member Rohit Chopra and was legal director at the Open Markets Institute, a think tank which has been highly critical of the Silicon Valley giants.

Early this year, Tim Wu, another Big Tech critic, was appointed to an economic advisory post in the White House.

Khan heads up the FTC amid a growing backlash against tech behemoths that have dominated key economic sectors and seen their influence grow during the pandemic.

Lawmakers and policymakers have in recent years been mulling the decades-old "consumer welfare" standard of antitrust enforcement, which allows for a largely hands-off approach for big firms as long as prices are not impacted.

Critics say this approach has allowed Big Tech firms to grow unchecked with unprecedented power over key sectors of the economy.