Delta Air Lines workers rallied Friday afternoon at Minneapolis-St. Paul International Airport as part of a coordinated campaign to unionize 45,000 employees.

More than 100 Delta employees chanted, "One struggle. One fight. Delta workers unite," and carried signs that read, "Most profitable airline, No sick pay" or "Delta Mechanics: Fixin' to be Teamsters."

Ramp, tower and cargo workers, flight attendants and mechanics from across Delta's system are actively trying to organize employees nationwide into three unions: the International Association of Machinists and Aerospace Workers, the Association of Flight Attendants and the International Brotherhood of Teamsters.

Dan McCurdy, a 25-year ramp employee who was a union member under Northwest Airlines' ownership, held up signed union cards to cheers before the picketing began.

"If Delta thought we were the best compensated in the industry, they wouldn't fear a vote," he told the crowd.

Among major U.S. airlines, Delta has the lowest percentage of unionized employees. Delta is the only U.S.-based mainline carrier without unionized flight attendants, fleet service and mechanics.

In a statement, Atlanta-based Delta said: "We support our employees' right to choose whether or not a union is right for them. We believe our direct relationship with employees is stronger, faster and more effective in driving improvements, which is why Delta employees have repeatedly rejected union representation over the past 20 years."

In all, only 20% of Delta workers are unionized, including nearly 15,000 pilots and 450 flight dispatchers. Earlier this year, its pilots won a new contract that their union says will boost average pay 34% through four years and cost the airline more than $7 billion.

"The big difference from the previous campaigns is everybody was going at it by themselves, which makes it more difficult," said DeLane Adams, a spokesman for the Machinists Union. "This time, it's a coordinated campaign with solidarity among all three unions."

Delta, the dominant carrier at MSP, reported this week a record quarterly profit of more than $1.8 billion as summer vacationers packed planes. Union organizers want workers to have a larger share of the company's gains and better benefits.

"I think we haven't succeeded because of all the interference by Delta meddling in our organizing drives," said Amanda Goodman Berry, a Delta ramp worker and union organizer.

A Delta spokesman declined to address the meddling allegations though the airline has a reputation for strong anti-union sentiment.

In 2019, Delta placed posters in breakrooms that encouraged employees to spend money on beer and video games rather than union dues. Workers took photos of the posters and posted them on social media, generating support from politicians and others.

This year's drive to collect enough signed cards for the National Mediation Board to schedule elections is the latest attempt since Delta and Eagan-based Northwest Airlines merged in 2008.

Half of employees plus one who are eligible for each union need to sign cards saying they want a vote to unionize for the process to move forward.