LOS ANGELES, June 11 — Thousands of University of California academic workers who went on strike at six campuses protesting administrators’ response to pro-Palestinian protests returned to the job yesterday under court order, but their union vowed more protests to come.

An Orange County Superior Court judge late on Friday granted a temporary restraining order sought by the university, which asserted that the walkout stemmed from non-labour issues and that it violated the no-strike clause in the union’s contract.

University officials had originally petitioned the California Public Employment Relations Board, but the panel twice rejected their requests for an injunction.

Unionised academic researchers, graduate teaching assistants and post-doctoral scholars walked off the job over what they called unfair labour practices in the university’s handling of pro-Palestinian demonstrations in recent weeks.

The work stoppage was organised by the United Auto Workers union Local 4811, which represents some 48,000 non-tenured academic employees across 10 UC campuses and the Lawrence Berkeley National Laboratory.

The protest strike began on May 20 at the UC Santa Cruz campus, and was expanded over the following two weeks to encompass UCLA, UC Davis near Sacramento, and campuses at San Diego, Santa Barbara and Irvine. Those six campuses account for roughly 31,500 UAW members. The UC system has a total of 10 campuses.

Continuation of the strike "would have caused irreversible setback to the students’ academic achievements and may have stalled critical research projects in the final quarter,” Melissa Matella, UC’s associate vice president for labour relations, said in a statement welcoming the restraining order.

Judge Randall Sherman set a hearing for June 27 to hear arguments on whether to extend the injunction. The union’s own strike authorisation expires on June 30.

UAW 4811 leaders denounced the ruling, saying the judge defied the authority of the Employment Relations Board by intervening in a labour matter outside the court’s jurisdiction.

Nevertheless, the union said its members were abiding by the court order. The UAW said it would focus its efforts on an upcoming grievance proceeding against the university.

Among other things, the union is demanding amnesty for grad students and other academic workers who were arrested or face discipline for their roles in campus protests against Israel’s military offensive in the besieged Palestinian territory of Gaza.

The strike marked the first union-backed protest in solidarity with a surge of pro-Palestinian student activism on dozens of US campuses in recent months.

The UAW said it was planning additional protests at UC Davis today and at UCLA tomorrow.

Union leaders have said a major impetus for the strike was the arrest of 210 people, including campus-employed grad students, at the scene of a Palestinian solidarity protest camp torn down by police at UCLA on May 2.

Masked assailants armed with sticks and clubs attacked the encampment and its occupants the night before, sparking a bloody clash that persisted for at least three hours before police restored order. — Reuters