LOS ANGELES – Hundreds of unionized workers including electricians, plumbers and carpenters are expected to begin a five-day strike at UCLA beginning at midnight tonight in the midst of contract negotiations with the university.

Officials with Teamsters Local 2010 warned that the strike could affect some campus operations, particularly at medical centers, and advised people to reschedule non-essential appointments. UCLA officials said, however, that they have a plan in place to "ensure that our hospitals and clinics remain open and fully operational and continue to serve the medical needs of our patients and the community." The walkout is expected to mirror a one-day job action the union held in November at UCLA and UC San Diego. Union officials contend its members have gone four years without a raise and the university has refused to negotiate wages covering past years "despite admitting to budgeting for those unpaid wages."

"Wages are so low that over 70 percent suffer from hunger or food insecurity, even while working full-time for one of the wealthiest universities in the country," according to the union. "More than 92 percent are paid too little to afford the basic necessities of life." UCLA officials countered that the university's most recent contract offer included an immediate 12.5 percent pay hike, a 2.25 percent signing bonus and 3 percent salary increases in 2017, 2018, 2019 and 2020. UCLA has been negotiating since Aug. 30 with the union, which represents about 600 skilled- trade workers at the university.

University officials called the planned strike "an unlawful, pre- impasse economic strike." "UCLA respects the contributions of its workers and shares in their desire to come to agreements on fair and competitive contracts in the near future," according to the university. "This resolution, however, will be achieved only if all parties engage in respectful and productive dialogue at the bargaining table."

The union also represent nearly 12,000 workers at UC campuses statewide, and a one-day strike affecting all UC campuses is scheduled for Tuesday -- the last day of the five-day UCLA strike.