Congresswomen Ayanna Pressley and Katherine Clark plan to join striking Harvard graduate students on the picket line Monday morning.

More than 2,400 members of the Harvard Graduate Student Union — or 90 percent of the union — voted last week to authorize a strike, and teaching fellows and research assistants are now withholding paid work including holding sections and office hours, conducting research work, grading coursework, and administering exams. The union says it is demanding “a strong contract with fair pay, comprehensive healthcare, and key protections against harassment and discrimination.

Pressley and Clark, whose districts include parts of Harvard, plan to be in Harvard Yard with the striking student workers at 10:30 a.m.

Last week, Clark and Pressley led the Massachusetts Congressional delegation in writing a letter to Harvard President Lawrence Bacow, asking him to “continue to set the bar by negotiating a first contract that will ensure fair treatment and strong workplace protections for workers, as well as uninterrupted education for your students.”

“At a time when the Trump Administration has been relentless in its efforts to eliminate workers’ statutory right to organize and unionize, we must be deliberate in our steadfast support for our union workers,” the letter said.