(Bloomberg) -- Massachusetts Democratic Senator Elizabeth Warren and House lawmakers are urging the US Transportation Department to disregard thousands of public comments orchestrated by JetBlue Airways Corp. in support of its $3.8 billion merger with Spirit Airlines Inc. 

In a letter written on June 21 to the Transportation Department, or DOT, Warren and lawmakers urged the department to “focus on genuine public input, not duplicative comments collected by a mendacious astroturf campaign.”

The campaign by JetBlue, which included a pre-written form in support of the merger, generated roughly 90% of the more than 10,000 comments on the Transportation Department’s public comment page. The comments are identical and are identified as coming from JetBlue and Spirit crew members who wrote that they believe the $3.8 billion merger will improve their lives, Bloomberg News previously reported. 

“A significant number of JetBlue crewmembers support our merger with Spirit and are excited about the opportunities it will bring,” said JetBlue spokesperson Doug McGraw. “These letters were completely voluntary, and JetBlue did not engage in any action towards Crewmembers, regardless of whether they submitted comments or if the comments were supportive or not.”

JetBlue CEO Robin Hayes has pushed back on criticism about the campaign, saying that while the company set up a tool to send the government identical comments from JetBlue and Spirit employees, each individual took action proactively and voluntarily.

“Thousands of JetBlue Crewmembers and Spirit Team Members – including many union members – legitimately expressed their support for the merger with the US Departments of Justice and Transportation,” Hayes wrote in a June 14 letter to Warren’s office.

“JetBlue been a consistent advocate for policies that promote airline competition and provide greater consumer choice,” Hayes wrote. “JetBlue’s acquisition of Spirit will advance those objectives.” 

Warren followed up with a separate letter to JetBlue on June 20, demanding answers to a list of questions about how JetBlue solicited the comments from employees. 

“A significant number of JetBlue crewmembers support our merger with Spirit and are excited about the opportunities it will bring,” said JetBlue spokesperson Doug McGraw. “These letters were completely voluntary, and JetBlue did not engage in any action towards Crewmembers, regardless of whether they submitted comments or if the comments were supportive or not.”

It’s relatively common for US airlines to ask employees to email or call members of Congress to lobby on behalf of a particular issue and sometimes provide suggested wording or forms that could be filled out. 

The Biden administration opposes the JetBlue-Spirit merger, saying it would lead to higher prices for consumers. 

The Justice Department in March sued to block the deal, while the Transportation Department said it would deny the airlines’ request for a license that would allow them to operate as a single carrier. 

A trial on the Justice Department’s suit is set for October.

JetBlue and Spirit contest the Justice Department’s suit, describing themselves as industry disruptors who can bring better service and lower fares for passengers.

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