SANTA CRUZ (CBS SF) — Hundreds of graduate students at the University of California, Santa Cruz are putting their jobs on the line in the midst of a strike demanding higher pay.

Those striking are specifically asking for a $1,400 per month cost of living raise, but they faced an ultimatum from the university on Friday: come back to work and release the grades you’ve been withholding from undergraduates or risk being fired.

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UCSC officials released a statement saying, “This is not a step we have taken lightly. Contingency plans will be developed to mitigate the issues this will create once we understand who has returned to work and who has not.”

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“I think graduate students have been very clear that the end of this strike comes when there is a guarantee of no discipline for participation in the strike,” said Veronica Hamilton, chair of the Student Workers Union and a UCSC PhD student.

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It was still unclear whether university administrators have fired any of the grad students on strike as of Monday evening.