The contract between the grocery chains and the union, which represents 23,000 employees in the Baltimore-Washington region, expires March 31.
"We are still hopeful for some meaningful progress," said Breanne Armbrust, a coordinator for Local 400. Outstanding issues include wages and benefits, she said.
The grocery stores have begun recruiting temporary workers, which the companies said was standard procedure during contract negotiations.
Local 400 has scheduled events on Tuesday at three Safeway stores, in Washington, Upper Marlboro and Alexandria, Va.