China-based solar panel-manufacturer Suntech Power Holdings Co. Ltd. announced late Thursday it would lay off 50 employees at its Goodyear plant, a move that will cut the firm’s workforce at the facility by half.

The Goodyear plant is its only U.S. factory.

The job cuts were triggered by a slowdown in plant production. There is a global oversupply of solar panels and recent import tariffs imposed by the U.S. government have led to higher production costs, the company said.

The Greater Phoenix Economic Council and Goodyear Mayor Georgia Lord aggressively lobbied the U.S. International Trade Commission to oppose tariffs that were approved by the panel earlier this month. The tariffs impact Suntech solar cells produced in China.

“We warned the International Trade Commission about the serious effects that tariffs on imported solar components would have on the livelihood of our workers in Goodyear,” Lord said in a statement. “Now, dozens of families find themselves suddenly unemployed thanks in large part to the federal government’s misguided decision announced last week,” she said.

Suntech will stop two of three production shifts.

Suntech will provide laid off workers with severance packages.

The company also offered to help them find other work, Lord said.

“Goodyear will continue to support this industry as it weathers this bad policy decision and works to grow over time its presence in our community,” Lord said.