Few industries were hit as hard as airlines when the coronavirus pandemic hit the US last year. To stop what looked like the imminent collapse of a major employer, the government stepped in with $15bn in support.

“We thank Congress and the administration for quickly passing legislation to protect the paychecks of tens of thousands of United Airlines employees,” said Frank Benenati, the United Airlines spokesperson.

A year on, the $5bn United Airlines received from the $2.2tn Coronavirus Aid, Relief, and Economic Security Act (Cares Act) has helped the airline hand back billions to shareholders and millions to executives. But for 2,500 United catering workers who struggled through the pandemic, it’s a different story. The company is now weighing plans to outsource their jobs to a contractor.

Jenkins Kolongbo has worked at United Airlines in Newark, New Jersey for four years as a food catering employee. In 2018, Kolongbo and his coworkers voted to unionize against the background of an aggressive anti-union campaign by United Airlines. Workers voted to join the Unite Here union with a 72% vote in favor.

Related: Furloughed US workers fight to return to their jobs after a year on pause

Now Kolongbo and 2,500 catering workers at United Airlines at five airports, Newark, Denver, Houston, and Honolulu could lose their jobs. “The company was not being fair and the best way to articulate and push for most of our rights is by having a union,” said Kolongbo.

United Airlines forcefully opposed the union election through 2018, even installing televisions set up throughout work areas where anti-union videos were played on repeat.

“We can’t protect you from the union if it is elected,” claimed a United Airlines anti-union flyer obtained by the Guardian. The flyer was titled “Stay United Vote No.”

An anti-union poster during the election told workers “travel privileges are not guaranteed, nothing is guaranteed during contract negotiations”.

Other anti-union videos and flyers focused on union dues and encouraged workers to vote ‘no’ in the union election, including one video featuring a stock photo of an arm getting tattooed with text above it stating, “a union is very difficult to remove if elected.”

Leading up to the union election, United Airlines alleged the union misled workers in obtaining union authorization cards, but the National Mediation Board found no evidence to support the charges. The investigation delayed the election, which took place in October 2018 after the union filed for an election in January 2018.

During the pandemic, Kolongbo explained his hours were cut from 40 hours a week to 30 hours per week, while other unionized departments at the airlines remained at 40 hours per week. In June, Kolongbo contracted the coronavirus and was out of work for three weeks. At least four of his co-workers passed away due to Covid-19. He was furloughed after CARES Act funding expired on 30 September and wasn’t called back until January.

He views the decision by United Airlines to outsource their work to a contractor as a way to avoid a first contract with the union.

“I believe that because we are in this struggle with them for a contract, for me I see it as another form of union busting. They probably want to intimidate us to have favorable terms in the contract for them,” Kolongbo added.

Amelton Archelus, has worked in airline catering at Denver International airport for over 20 years. He also experienced reduction to his work hours at United Airlines during the pandemic and is concerned over the prospect of losing his seniority, pay, benefits, and possible job with the switch to a contractor.

“You lose everything: seniority, pay, benefits. The contractor can say they don’t want to hire you,” said Archelus.

He pointed out that United Airlines had made the decision to consider outsourcing his job and undermine the workers’ union even after it had spent $8.57bn on stock buybacks between 2014 and 2019, committed to paying cash awards worth $7.5m to top executives and is projecting its profit margins will surpass 2019 profits by 2023 as it anticipates the travel industry rebounding from the pandemic.

Congresswomen Sylvia Garcia and Eleanor Norton wrote letters to the US Treasury and United Airlines earlier this month demanding information on how the airlines has used Cares Act funding, and requesting the Treasury department obtain a commitment from the airlines to rescind the outsourcing request for proposals and any executive bonuses in any payroll support extension agreement.

In Houston, Texas, Fernando Herrera, a driver for United Airlines in the catering department for 18 years, is worried about losing his health insurance as he’s experienced health issues since having a heart attack at work, and his wife and son rely on the insurance.

“I feel betrayed. We’ve served so many years to this company. We’ve been breaking our backs, not only me, but many of my co-workers who have worked here most of our lives,” said Herrera, who expressed dismay that the airlines has yet to negotiate a contract with the union since 2018, but instead is now pursuing plans to contract out their jobs. “United received so much money to keep workers working. We’re still in the middle of a pandemic and at my age now it’s very difficult to start all over and find another job.”

A spokesperson for United Airlines said the airline values their relationship with employees and union representatives, and noted several contractors have employees represented by unions, though they did not comment on the first contract negotiations with the catering workers.

“Although United has submitted an exploratory Request For Proposals [RFP], we have not made any decisions to move forward with a third-party vendor at this time. Given the unprecedented impact of Covid-19 on our business, United continues to explore ways to do things differently and become more efficient wherever we can – this RFP is part of that effort,” the spokesperson said in an email.