HMSHost workers and union representatives walk together as UNITE HERE Local 355 threatens a strike against HMSHOST at the Miami International Airport on December 12, 2014 in Miami, Florida.

Hundreds of airline catering workers are protesting this week at some of the largest U.S. airports to demand higher wages and better benefits during what's expected to be a record Thanksgiving travel period.

Some of those workers, who prepare and deliver meals to airlines and are represented by the Unite Here labor union, are planning to block airport roads or stage sit-ins around ticket counters and pre-security areas on Tuesday at airports including those serving New York, Los Angeles, San Francisco, Miami and Philadelphia.

Others plan to picket and hand out pamphlets about their demands, according to the union, which represents more than 20,000 airline catering workers. Airlines for America, a trade group, expects a record 31.6 million travelers to fly on U.S. airlines during the 12 days around Thanksgiving, up nearly 4% from last year.

The protests are the latest demonstrations by emboldened workers who are demanding a bigger share of corporate profits, which have surged since the last recession more than a decade ago. Airline workers have been particularly visible this year after airlines reported disruptions they said were due to workers trying to gain leverage in contract talks. President Donald Trump signed a bill ending the longest-ever government shutdown in January, hours after a shortage of air traffic controllers disrupted flights.

The workers are employed by LSG Sky Chefs and Gate Gourmet, which big airlines subcontract to provide on-board food and beverages. The union contends that some workers don't earn enough to keep up with the cost of living and is arguing for a nationwide wage of at least $15 an hour.

Robert Ortiz said he makes $18 an hour driving a catering delivery truck at New York's John F. Kennedy International Airport for LSG Sky Chefs, which is controlled by Deutsche Lufthansa.

"Eighteen dollars in New York is nothing," said the 32-year-old father of three who lives in Queens. He said he wants to earn at least $22 an hour. "People don't really know what's going on to get their flights on time," said Ortiz. "We know what we deserve. We're not asking that much."

Thousands of these food service workers, currently in contract talks, voted this summer to strike, but airline workers fall under the Railway Labor Act, which requires the permission of the National Mediation Board, whose members are appointed by the president, to do so.

Gate Gourmet has "made significant improvements for our people in wages and benefits across the U.S. and our negotiations with the union to date include additional investments in our people," said spokeswoman Nancy Jewell. It said talks with the union are scheduled for December.

"In the meantime, we operate under the Railway Labor Act, which preserves the current terms and conditions of our existing National Master Agreement labor contract and prevents operational disruptions," she said. "As always, we remain focused on excellent service to our airline customers and the passengers they serve."

LSG Sky Chefs spokesman David Margulies said the caterer and a federal mediator have been negotiating with the union since May.

"While this is a short period of time to negotiate a complex labor agreement, we feel progress is being made with the help of the federal mediator. We remain committed to negotiating in good faith," he said.

American Airlines contracts outside kitchens to supply its meals and said that the union and catering vendors talks will likely lead to higher pay and benefits, which would drive up airline costs.

"We understand that new labor contracts between Unite Here and LSG Sky Chefs and Gate Gourmet will result in increased costs for their many airline customers, including American," said American Airlines spokesman Josh Freed. "We are not in a position to control the outcome of their negotiations or dictate what wages or benefits are agreed upon between the catering companies and their employees."