A federal judge denied the request from the Southwest Airlines pilots union to block the airline’s vaccine mandate under the government’s latest COVID-19 requirements.

The union argued that COVID-related policies, including the vaccine mandate, within the airline needed to be negotiated with the union. However, on Tuesday, Judge Barbara Lynn said the airline had the right to move forward with imposing the vaccine mandate.

“Requiring Southwest employees to be vaccinated against COVID-19 will likewise improve the safety of air transportation, efficiency of Southwest’s operations, and further the [collective bargaining agreement’s] goal of safe and reasonable working conditions for pilots,” Lynn wrote in her ruling.

Southwest employees must be fully vaccinated against COVID-19 by Dec. 8 or show they have received a medical or religious exemption. 

Following the ruling, the labor union revealed it was disappointed and “are currently considering next steps.”

Southwest is expected to cut back on its number of flights in December to avoid the same mass cancellations it experienced in October due to employee shortages, air traffic control issues, and weather delays.

“We have reined in our capacity plans to adjust to the current staffing environment, and our on-time performance has improved, accordingly,” said CEO Gary Kelly. 

“We are aggressively hiring to a goal of approximately 5,000 new employees by the end of this year, and we are currently more than halfway toward that goal.”

Southwest’s push for the COVID-19 vaccine comes after President Biden ordered companies with more than 100 employees to have staffers vaccinated or face penalties.

In an interview on CNBC's "Squawk on the Street,” Kelly revealed he doesn’t agree with the mandate but feels forced to impose it after Biden's orders.

“I’ve never been in favor of corporations imposing that kind of a mandate. I’m not in favor of that. Never have been,” Kelly said at the time.

“But the executive order from President Biden mandates that all federal employees and then all federal contractors, which covers all the major airlines, have to have a [vaccine] mandate ... in place by Dec. 8, so we’re working through that.”

Southwest Airlines plans to trim back its plans while it hires more people Southwest Airlines plans to trim back its plans while it hires more people Photo: AFP / KAMIL KRZACZYNSKI