The U.S. First Circuit Court of Appeals has agreed to an expedited ruling for JetBlue and Spirit's appeal of their rejected merger.
Arguments in the case are now tentatively set for June.
"Extensions will be strongly disfavored," the First Circuit said in an order on Friday.
JetBlue and Spirit had requested an expedited appeal process so a decision could happen before the July 24 closing deadline of their merger agreement.
In a Jan. 16 ruling, U.S. District Court Judge William Young determined that the proposed merger doesn't meet legal muster because it would hurt Spirit's budget-conscious customers in nearly 300 nonstop and connecting markets around the country.
JetBlue and Spirit are arguing that Young misapplied the governing antitrust law, known as the Clayton Act, by focusing too heavily on the customers who rely on Spirit's ultralow-cost model and whether a loss of discount service could be completely replaced on a route-by-route basis.
The Clayton Act, the airlines argue, is worded to prevent a substantial reduction in competition but does not require mergers to preserve the exact same level of competition.