A federal judge considered Thursday morning whether to grant speedy hearings for two massive health insurance mergers the federal government is trying to block.

Anthem asked U.S. District Judge John Bates for its trial to start by Oct. 17 and end by Dec. 31, saying a later start date would jeopordize its ability to merge with Cigna by an April deadline, costing the company a $1.85 billion breakup fee. Anthem wants the trial to end by Dec. 31.

Likewise, Aetna wants an October trial for its proposed takeover of Humana.

Bates said Thursday that an October trial for Anthem would put it on a "very fast" schedule, according to Bloomberg News.

The Justice Department, which has said it wants the trial held in February so it can conduct pretrial litigation, urged the judge to ignore the merger deadlines. In a statement this week, the agency noted the large size of the proposed mergers — a $37 billion deal between Aetna and Humana and a $54 billion deal between Anthem and Cigna.

"The scope of each of these matters is enormous," the Justice Department said. "These cases challenge the largest mergers ever proposed in the $3 trillion health-insurance industry, and threaten harm to millions of consumers across the country. Given what is at stake, this court should allow both sides a reasonable opportunity to develop the relevant evidence in discovery and to present that evidence at trial."