Drug giant Pfizer could begin making hundreds of layoffs at its manufacturing plant in Rocky Mount as early as Tuesday.

Pfizer had disclosed plans earlier in the summer to reduce the size of the work force at the plant, which it acquired from Hospira in 2015.

Asked about talk that some 400 workers are expecting to be let go on Tuesday, a Pifzer spokesperson restated comments made earlier in the year.

“Due to recent changes in market demand for certain products, Pfizer will reduce manufacturing volume and associated staffing levels at the legacy Hospira Rocky Mount, NC facility in the second half of 2016,” the company said.

“Previously announced investments in a new state-of-the-art sterile injectable manufacturing facility and new quality laboratory at the site will continue as planned. The Rocky Mount site remains an important site in Pfizer’s Sterile injectable supply network.

“Based on current information, we expect the production level changes will impact a few hundred full time roles in the second half of 2016.”

Some 2,000 people work at the Pfizer complex.