Sen. Elizabeth Warren is writing legislation that would ask regulators to review two decades of megamergers across the economy and then empower the federal government to reverse them.

The Anti-Monopoly and Competition Restoration Act, as it is tentatively titled, would be one of the most sweeping pieces of anti-monopoly legislation in Congress. Warren is expected to introduce the Senate version of the bill while Rep. David Cicilline, D-R.I., will introduce a House companion. It was unclear when the bill would be introduced.

According to draft legislation obtained by Bloomberg News, Warren's bill would alter the current antitrust approach, which is based on the consumer welfare standard, assessing the impact of mergers, primarily through their impact on prices and quality of  products or services. Warren's legislation would instead task regulators with reviewing mergers with different criteria, including the impact workers and innovation, and empower regulators to reverse mergers that have occurred in the past two decades.

The bill would also propose a ban on future mergers -- with a few exceptions, like when a company is in danger of insolvency -- when one company involved has annual revenue greater than $40 billion or when both of the companies involved have sales of topping $15 billion a year.

Some critics of the legislation say it is unlikely ever to be adopted. 

“The way I read it is that Elizabeth Warren is trying to make a political statement in the course of her campaign,” Barak Orbach, a law professor at the University of Arizona, told Bloomberg. “It’s likely to have negative effects on antitrust enforcement, so I just don’t see the upside other than for the campaign.”

Warren has indeed made antitrust enforcement a major theme of her presidential campaign. Earlier this year, she called for breaking up major tech companies, including Amazon, Google and Facebook. 

"Today's big tech companies have too much power -- too much power over our economy, our society, and our democracy. They've bulldozed competition, used our private information for profit, and tilted the playing field against everyone else. And in the process, they have hurt small businesses and stifled innovation," Warren wrote in a Medium post introducing her proposal. "That's why my administration will make big, structural changes to the tech sector to promote more competition — including breaking up Amazon, Facebook, and Google."