More than 2500 students sat down in the Student Union Plaza at the University of California at Berkeley yesterday afternoon to prevent a university police car from arresting the leader of an ad hoc committee protesting recent university restrictions of campus politics.

The trouble started when the dean of students banned organizations from soliciting membership and funds at outdoor tables on campus. The full spectrum of Berkeley's political make-up, from Goldwaterites to Socialists, rallied together, and Wednesday several groups set up tables in deliberate defiance of the dean's edict.

That night, 400 demonstrators jammed into Sproul Hall, the university's administrative office. At 12:30 a.m., the university chancellor came before them and announced the "indefinite suspension" of eight students who had participated in the civil disobedience.

Yesterday morning, their anger whetted by the suspensions, students continued to man the outlawed tables. Police approached one of the leaders, Jack Weinberg, and asked for his ID card. When he refused, saying it would lead to his suspension, the officers placed him under arrest. Weinberg went limp, and when the university police carried him to a waiting patrol car, hundreds of students sat down on all sides of the vehicle, and prevented it from moving.

The police insisted that Weinberg was under arrest, and said they intended to wait until the mob moved.

But instead of moving, the crowd of students swelled to 2500. Another leader of the protest, Mario Savio, of Berkeley Friends of SNCC, tried to address the students, but couldn't be heard. So he removed his shoes and climbed stop the police car. Savio, whom the San Francisco Chronicle described in its afternoon edition as a "silver-tongued orator," urged the crowd to stay until all their demands were met.