A federal judge in Washington blocked Anthem’s proposed $54 billion acquisition ofCigna., handing antitrustenforcers a second win in two months againsta major merger in the health insurance sector.

The U.S. Justice Department sued in July to block Anthem’sdeal and Aetna’s proposed $37 billion tie-up with Humana, allegingthe mergers would amount to an “unprecedented consolidation in thehealth insurance industry.” In the suit against the Anthem andCigna merger, federal antitrust lawyers said the deal wouldhurt competition for millions of consumers whoreceive health coverage from national employers.

Anthem and Cigna’s defense, at trial, was dogged by tensionbetween the two companies over the execution of the merger. In thebuildup to trial, U.S. District Judge Amy BermanJackson was struck by the feud, at one point remarkingthat it was a “bizarre situation” to make scheduling accommodationsfor a deal Cigna appeared to no longer desire.

In her ruling on Feb. 8, Jackson described that discord as the“elephant in the room.”

“In this case, the Department of Justice is not the only partyraising questions about Anthem’s characterization of the outcome ofthe merger: one of the two merging parties is also actively warningagainst it,” Jackson wrote.

Cigna officials, Jackson said, “provided compelling testimony”that undermined the forecast of future savings. “[T]he disagreementruns so deep that Cigna cross-examined the defendants’ own expertand refused to sign Anthem’s findings of fact and conclusions oflaw on the grounds that they ‘reflect Anthem’s perspective’ andthat some of the findings ‘are inconsistent with the testimony ofCigna witnesses,’” the judge wrote.

Jackson’s ruling was the second in weeks against consolidationin the health care arena.

U.S. District Judge John Bates in January, citing “seriousconcerns,” enjoined the Aetna-Humana merger. A status conference is setfor April 5.

Jackson rejected Anthem’s argument that the deal would createefficiencies that would save national account customers a combined$2 billion in medical expenses. The judge said the claimed savingsare not “merger-specific, they are not verifiable, and it isquestionable whether they are ‘efficiencies’ at all.”

She also said the Justice Department lawyers had “carried theirburden to demonstrate that the proposed combination is likely tohave a substantial effect on competition in what is already ahighly concentrated market.”

Anthem’s lawyer, White & Case partner Christopher Curran,declined to comment on the decision, noting that the case remainspending. A lawyer for Cigna, Paul Weiss partner Charles Rule, wasnot immediately reached for comment.

The ruling Wednesday came as the Senate confirmed U.S. Sen. JeffSessions asU.S. attorney general. Sessions’ approach toantitrust issues remains a question to many corporate defenselawyers.

Trump hasn’t given any clear indications of how hisadministration will approach antitrust enforcement. He hasrepeatedly said he’s not in favor of AT&T Inc.’s proposedtie-up with Time Warner Inc. “It’s too much concentration of powerin the hands of too few,” Trump said in October.