For the eighth time in 35 years, Yale workers will begin a strike this morning, joined on picket lines by some graduate students and workers from Yale-New Haven Hospital.

The five-day strike marks the culmination of more than a year of unsuccessful contract negotiations between Yale the unions, locals 34 and 35. The strike also comes nearly 14 years after the Graduate Employees and Students Organization began seeking recognition from the University.

Union leaders said the strike may continue when students return from spring break March 24, but many union members said they expect the strike to end Friday.

Talks between Yale and locals 34 and 35 have stalled in recent months as the two sides have clashed over contracts, pension plans and unionization efforts at the graduate school and at the hospital.

Throughout the week, striking workers and graduate students will picket around campus and hold daily rallies. National labor leaders and social activists will visit campus to lead the striking workers.

Striking members of locals 34 and 35, which represent nearly 4,000 clerical, technical, service and maintenance workers, will not work on campus this week. GESO members who strike will not teach sections and will refrain from entering any University facilities or doing research.

Striking workers and graduate students will form a picket line rally at the corner of Wall and College streets this morning.

Union spokesman Bill Meyerson said picket line participation will reach its peak level around 9 this morning. He said picketing should continue until about 1 p.m., at which point picketers will scatter around campus and continue demonstrating through the afternoon.

Meyerson said the day’s activities will culminate with Jackson’s march, which will begin at 5:30 p.m. By union leaders’ estimates, thousands of union supporters will proceed from Wooster Square to Woolsey Hall, where Jackson will address union supporters, Meyerson said.

Service Employees International Union President Andrew Stern will address workers on Tuesday, AFL-CIO President John Sweeney will speak on Wednesday, and Princeton religion professor Cornel West will come to campus on Thursday. Union leaders have given each day of the strike a theme: today, the idea of a social contract; tomorrow, health care; Wednesday, labor; and Thursday, GESO. Friday’s theme, celebration, will include a party Friday afternoon.

Yale spokesman Tom Conroy said University officials will try to make sure the strike does not disrupt many aspects of campus life.

Conroy said he was disappointed by the unions’ decision to hold a walkout. He said the purpose of the strike was to gain publicity and attention rather than to disrupt University operations.

“We do regret that they felt it was necessary to call a strike, but the University will be fully operational this week,” he said.

Conroy said the two sides have scheduled three bargaining sessions for the week after the strike. He said union members will return to work next weekend.

Union negotiators are asking for raises of 6 to 10 percent over four years. Yale has offered raises of more than 4 percent a year over six years for Local 34 and more than 3 percent a year for Local 35.

Union leaders have said that the two sides have not reached an agreement because the University does not send key decision-makers like Yale President Richard Levin to the bargaining table. University officials maintain that union leaders are focused on the organizing drives of GESO and hospital workers.