It has been a particularly difficult 12 months for both Spirit Airlines  (SAVE) – Get Free Report and JetBlue Airways  (JBLU) – Get Free Report — last week, a federal court blocked the latter’s efforts to acquire the budget airline for $3.6 billion over concerns that such a merger would create an anti-competitive environment.

While the airlines initially responded by saying that they would be “reviewing the situation” and “evaluating next steps,” the idea of an appeal or other last-minute Hail Mary is looking increasingly less likely as JetBlue told the Securities and Exchange Commission (SEC) that the deal may be abandoned because it may not be able to meet “certain closing conditions” required by the merger before the Jan. 28 deadline.

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“The merger agreement may be terminable on and after January 28, 2024,” the airline says in the 8-K filing.

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After news of the filing was first published by Bloomberg, Spirit stock immediately tanked by nearly 20% by the afternoon of Jan. 26. Amid both the court decision and several consecutive quarters of poor financial performance, Spirit shares have fallen by more than 64% in the last month at what is currently $6.04.

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While Spirit went the other way and said that “there is no basis for terminating the Merger Agreement” and that it “will continue to abide by all of its obligations,” JetBlue’s loss of confidence in the deal’s ability to go forward served the definitive punch for many investors who are increasingly looking to sell.

JetBlue shares, in turn, have fared much better than Spirit ones despite much fluctuation in the days leading up to and immediately after the Jan. 16 decision about the merger. At $5.46, they are down 4.62% from last month but up 2.34% in the last 24 hours and 3.70% in the year to date.

Invested in either Spirit or JetBlue? Here are the latest updates you should know about

TD Cowen analyst Helane Becker had formerly published a note saying that this could be a “positive for JetBlue as business at Spirit turned negative between the time the merger was announced to now” while the best course of action for Spirit would be a Chapter 11 bankruptcy.

If the merger fails to go through, JetBlue had earlier agreed to pay $70 million to Spirit and $400 million minus the sum of the approval prepayments to Spirit stockholders who were counting on the merger. 

JetBlue’s interest in acquiring Spirit was based on the desire to grow the New York-based airline further into a major national airline while the judge felt that it would give JetBlue over 10% of the U.S. market share and allow it to drastically increase prices while leaving consumers with fewer low-cost airlines to choose from. Two-thirds of the market share is already controlled by the country’s fourth largest airlines.

“JetBlue continues to evaluate its options under the Merger Agreement,” the airline said further in the SEC filing. “Unless and until such time as the Merger Agreement is terminated pursuant to its terms, JetBlue will continue to abide by all of its obligations under the Merger Agreement.”