The Transportation Security Administration has temporarily frozen hiring and overtime so it can afford across-the-board cost-of-living raises for employees, a move that leaders of the agency’s employee union said could lead to long waits at airport checkpoints during spring break.

Hydrick Thomas, the union’s president, said agency officials told him last week that the freezes would be in place until April or May. That could leave security checkpoints short-staffed, he said.

“You’re going to have long lines,” Thomas said. “That’s just the way it works.”

Thomas said that he hadn’t seen anything in writing about the change but that the agency’s regional security directors were informed in a phone call last week. Another union official said he was told of the plan by the security director at the airport where he works.

A Democratic congressional aide, who was not authorized to comment publicly, said the House committee that oversees the TSA was told that the agency had to limit staffing to cover the cost of the average 3.1 percent pay raises for federal employees included in a spending deal passed at the end of last year.

In a statement, the TSA said it was seeking to use its resources as well as possible.

“In anticipation of another record-breaking summer travel season, the Transportation Security Administration is managing resources by prioritizing overtime to the busiest of travel periods,” the statement said. “Additionally, TSA will continue to assess applicants for entry into TSA, and will conduct two extended hiring windows to coincide with the busy summer travel season.”

A TSA spokeswoman said the freeze would not impact spring break travel because the agency has already hired additional officers to ensure that they will be ready for spring break.

“They are here and working,” she said. “The pause in hiring will be lifted in late April to ensure that additional TSA officers are hired, undergo training, certification and go through some on-the-job training by the time summer travel season arrives.”

An internal TSA bulletin sent Friday that was reviewed by The Washington Post suggests the effects of the freeze were already being felt.

The bulletin said wait times hit 40 minutes at a checkpoint at Honolulu’s Daniel K. Inouye International Airport, “due to a large amount of passenger build up with national overtime revocation resulting in restricted checkpoint capabilities.”

The same day, the American Association of Airport Executives sent an alert about the freeze and trying to gather more information. The message said that some airports with especially high spring break traffic might be exempt but that the group had not received any official word from the TSA.

“Given the concerns we are hearing from our airport members, AAAE staff have raised alarm bells over the hiring and overtime freeze to Members of Congress,” the message said.

While the TSA said in its statement that it was prioritizing resources for the busiest time of the year, information from the Bureau of Transportation Statistics shows passenger counts jumped last March after the two quietest months of the year in January and February.

The TSA employs some 47,000 officers who screen passengers as they prepare to board flights. The agency deals with high employee turnover, which means it has to continually hire and train new officers to replenish it ranks.

“We always have a shortage of manpower,” said Thomas, who is the president of American Federation of Government Employees TSA Council 100.

The agency is seeking to take steps to resolve some of its chronic staffing issues, saying the loss of experience when employees leave “can contribute to security risks across the aviation system.”

In its budget proposal for the coming year, the TSA outlined a plan to provide its officers with raises based on tenure, in line with the practice at other government agencies, and offer other raises to especially skilled screeners.

Joe Shuker, a union vice president responsible for the region that includes the Washington area, said because of low pay, screening officers rely on overtime to make ends meet. Extra hours are usually easy to come by, Shuker said.

“We can’t keep people,” he said. “They spend so much money training people and then they leave. . . . We’re losing people to Chick-fil-A in the airport.”