Some of the demonstrators carried signs reading "Katsav to jail", "There is no light rape" and "a sex offender ruling the country." Some called on Mazuz to resign.
At the end of the rally, hundreds of demonstrators blocked Ibn Gvirol Street. They were evacuated by the police and some were arrested.
Education Minister Yuli Tamir told Ynet before the rally, "I think this is insolence. What is happening here is severe. We call for a court hearing so that the court can decide."
Knesset Member Zahava Gal-On called from the stage, "Meni Mazuz, you are a coward. You were frightened by the top lawyers." The audience chanted in response, "We shall not give up."
Attorney Kinneret Barashi, the lawyer of complainant A who worked at the President's Residence, was moved by the thousands of people who flocked to the square.
"I am pleased to see that everyone understands that this is not one person's specific problem, but that this is a democratic state. It is unthinkable that Mazuz would give the president such a deal. The case should have been transferred to the court," she said.
The rally was hosted by radio and television broadcaster Merav Michaeli and was also attended by Labor MKs Shelly Yacimovich and Nadia Hilou. The demonstration was held under the banner "The president's dignity was saved, let's save our own dignity."
Education Minister Tamir said in her speech, "We are here in order to protest an immoral decision which takes us years back in time. I was ashamed when I heard Katsav's attorneys saying that A should return to her anonymity. We will not allow this issue to be taken off the agenda.
"There is no person who can come out clean with such a plea bargain. In school we teach the students to honor each other. If this deal goes through, we will not be able to educate the children.
"This deal stains all of us, and we do not deserve to have Katsav's stain inflicted on the entire Israeli society. Perhaps this is the moment when all of us must tell the Israeli public – enough is enough. Women shall not be hurt, their dignity shall not be humiliated – not through acts, not through touching and not through kisses. We demand a trial and a real trial."
Rabin Sqare demonstration (Photo: Niv Calderon)
MK Hilou said, "The demonstration at the square is the real puzzle of the Israeli society and it conveys a very important message on an extremely painful issue. We are a front here and we all say no to that deal and call on Attorney General Meni Mazuz to go back on the deal."
MK Yacimovich told Ynet, "It is pleasing to see that there are not only women here, but an entire consensus of the entire public in Israel. An unreasonable thing happened here. We believe the complainants, the police believe the complainants, and therefore this issue must reach the court."
Dr Zvi Shiloni from Midreset Sde Boker said, "My wife and I, together with our neighbors, came from the far Negev because we feel that what is happening here is not right. This decision on a plea bargain symbolizes a complete collapse of the legal system."
On Sunday, after Katsav is indicted, The Movement for Quality Government in Israel and women's organizations plan to petition the High Court of Justice against the attorney general, demanding that he go back on the plea bargain.