The U.S. Department of Justice is suing to block two mega healthcare mergers, saying the acquisitions would “fundamentally reshape the health insurance industry” to the detriment of consumers.

The antitrust lawsuits were announced Thursday by Attorney General Loretta Lynch in response to Anthem’s $54 billion proposal to acquire Cigna and Aetna’s $37 billion bid to takeover Humana.

“If allowed to proceed,” Lynch said in prepared remarks, “these mergers would fundamentally reshape the health insurance industry. They would leave much of the multi-trillion dollar health insurance industry in the hands of three mammoth insurance companies, drastically constricting competition in a number of key markets that tens of millions of Americans rely on to receive healthcare.”

“If the ‘Big Five’ were to become the ‘Big Three,'” Lynch said, referring to the major health insurance providers, “not only the bank accounts of the American people would suffer—but also the American people themselves.”

According to USA Today:

In particular, USA Today noted, “[t]he Aetna-Humana deal would combine two of the four largest providers of Medicare Advantage plans, threatening to drive up costs for certain seniors, and would undermine competition in public exchanges in Florida, Georgia and Missouri, the government said.”