The stagehands who work behind the scenes at the Kennedy Center authorized a strike Thursday morning, more than a year after their contract expired, saying that ongoing talks seem unlikely to result in a new deal. The two sides remain at odds over several key issues, including staffing levels, wages and overtime pay, according to the union.

The unanimous vote by members of Local 22 of the International Alliance of Theatrical Stage Employees (IATSE) comes days before the Broadway hit “Hadestown” — the first major touring show to play at the Kennedy Center since the pandemic — arrives in Washington for a three-week engagement.

Representing Broadway’s return, “Hadestown” offers a high-profile deadline for negotiations that have dragged on for a year, union officials said. A strike could cancel some or all of the 24 performances during the show’s Oct. 13-31 run, as well as other scheduled events.

“We are very confident most of the Kennedy Center’s operations will be shut down if they let this go all the way,” said David McIntyre, president of Local 22, which represents about 400 stagehands, about a possible strike. “We have been trying to explain to them that we are unwilling to work without a contract indefinitely. That message was not getting through.”

Local 22 is counting on members of other unions at the arts center to support their cause, McIntyre said. The Kennedy Center has collective bargaining agreements with 15 unions.

Eileen Andrews, the center’s vice president of public relations, expressed a different view of where negotiations stand. She said talks that extended into Thursday morning resolved all of the issues except one: the use of IATSE stagehands for programs at the Reach and at off-site events (such as the National Symphony Orchestra’s “In Your Neighborhood” program).

“This would entail a fundamental shift in how we manage, staff, and budget for extended programming, impacting both events held in the community and outside events held at the Kennedy Center,” she said in a statement. “A work expansion of this scale would be cost-prohibitive and unsustainable.

The union has not notified us of a work stoppage. At this time, all performances and events will proceed as scheduled,” she added. “Patrons will be advised immediately should this change.”

The four-year agreement with the stagehands and the arts center expired in September 2020, six months after the pandemic closed the arts center and put most of the union members out of work. Union officials said they first offered to extend the previous deal for a year, reflecting the seriousness of the crisis and the fact that most of their members were unemployed. They next proposed a 10 percent wage cut for the duration of the pandemic.

The Kennedy Center sought permanent cuts, McIntyre said. The center’s initial proposals of 40 percent were reduced, he added, but it still wants to cut wages and overtime. The Kennedy Center’s Andrews said these issues have been resolved.

McIntyre disagreed. “That’s a very optimistic interpretation,” he said, explaining that the wages and benefits package and overtime is tied to the use of IATSE members at the Reach and in the community.

“The Kennedy Center is unique and alone in demanding massive permanent cuts from the get-go,” Local 22 Business Agent Ryan Chavka said, noting that the union was able to reach agreements that included “reasonable concessions” with other area venues.

The strike authorization could affect dozens of events. In addition to “Hadestown,” the arts center’s schedule includes concerts by the National Symphony Orchestra, German tenor Jonas Kaufmann and banjo player and fiddler Jake Blount, and performances by comedian Hasan Minhaj and the dance company Ronald K. Brown/Evidence. “Beautiful: The Carole King Musical” and “Ain’t Too Proud — The Life and Times of the Temptations” are expected in December, with 11 more Broadway shows coming in 2022.

McIntyre, Chavka and other union members met with art center officials, led by Senior Vice President Ellory Brown, on Wednesday via Zoom. The talks continued for 16 hours until after 1 a.m. Thursday.

Andrews said the arts center is disappointed that the negotiations have stalled.

“The ongoing circumstances of the covid-19 pandemic have put the Kennedy Center in an unpredictable and uncertain financial position, resulting in a $9 million deficit for the recently completed fiscal year (2021) and leaving a projected deficit of $7 million for 2022,” she said in an email. “Given the reality of our financial situation and the ongoing uncertainty of the pandemic, the impacts on our programming, our community, and to our budget make expanded jurisdiction unsustainable. After a year of unprecedented hardship, the Center has been able to reopen its stages and restore work for the union’s members. We remain committed to working with our stagehands to identify a path forward and reach an agreement that reflects the complexities of the pandemic landscape and allows us to continue the world-class performances that are our purpose.”

A vote to authorize a strike does not mean it is inevitable. The musicians of the Kennedy Center Opera House Orchestra (KCOHO), the 61-member ensemble that performs for opera, musical theater and ballet, authorized a strike last month, as the arts center was preparing for its 50th anniversary celebration on Sept. 14, said Peter de Boor, a French horn player who is chairman of the orchestra committee. The musicians did not act on the vote immediately and continued to negotiate to avert a strike.

During rehearsals for the production, which was broadcast on public television Oct. 1, NSO musicians and arts center stagehands wore wristbands and buttons supporting the KCOHO. It was an implicit signal that they would not cross a picket line, should the Opera House Orchestra strike, de Boor said.

The show of solidarity was instrumental to the orchestra reaching three-year deals with the Kennedy Center and the Washington National Opera, de Boor said. “It indicated to the arts center that the failure to reach an agreement would lead to the disruption of this highly anticipated event,” he said.

The KCOHO’s new contracts with the WNO and the arts center include a 9 percent pay cut in the first year but restore pay to almost pre-pandemic levels by the final year, de Boor said. They are retroactive to Sept. 1 and end Aug. 31, 2024.

The KCOHO had renegotiated its agreements in 2020 to include 25 percent cuts to provide relief to the struggling institutions, de Boor said. But the orchestra rejected the Kennedy Center’s proposal to continue those cuts now that the center has reopened. Most of the proposed cuts came in the form of reduced work guarantees (the minimum amount of work each year), rather than reduced salary scale.

“The center seems to be making a choice to offer less of the traditional art forms of opera and ballet and more commercial theater and that appears to be for financial reasons,” de Boor said. “We reject that choice. We perform for ballet and opera, and we don’t want to be diminished. This is a conflict that will likely arise again.”

The KCOHO musicians would support the stagehands should they strike, de Boor said.