WASHINGTON (Reuters) – A U.S. judge who has been asked to sign off on a government agreement that allowed CVS Health Corp to buy health insurer Aetna ordered a hearing for April 5.

Judge Richard Leon of the U.S. District Court for the District of Columbia issued the order on Thursday, saying that he wanted the hearing to discuss which witnesses, if any, should testify before he decides whether to approve the government’s deal with the companies.

The $69 billion transaction closed in November.

The Justice Department approved the merger of CVS, a U.S. pharmacy chain and benefits manager, and Aetna in October on condition that Aetna sell its Medicare prescription drug plan business to WellCare Health Plans Inc. That deal has also closed.

Judges usually approve merger agreements that the government strikes with companies with little fanfare but Leon has balked. In December, he said he was “less convinced” than the government that the asset sale to WellCare would resolve antitrust concerns.

Critics of the deal include the American Medical Association and the AIDS Healthcare Foundation.

Pending Leon’s approval, CVS agreed to temporarily allow Aetna to independently make critical product, pricing and personnel decisions.

Both CVS and the Justice Department declined comment.