"Resign" read a banner headline in the mass-selling Yediot Aharonot daily newspaper, echoing calls across the political spectrum for the president to step down from his post.
Katsav is expected to make a public statement later on Wednesday, a day after Menahem Mazuz, the attorney general, said he intended to charge the 61-year-old married father of five with rape, sexual harassment, breach of trust and accepting bribes.
Zehava Galon, a member of the Meretz Party, said Katsav should have immediately resigned on Tuesday when Mazuz confirmed his intention to charge the president.
She she would start collecting the 20 politicians' signatures necessary to convene an impeachment debate in parliament, without waiting for Katsav's statement.
She told Israeli Radio: "We are starting the process of signing up members of parliament to bring about the impeachment of the president."
"After examining all the available evidence, the attorney general has reached the conclusion that there is sufficient alleged evidence to file an indictment against the president," Israel's justice ministry said on Tuesday.
A final decision on the indictment will be made only after a hearing, where Katsav will be allowed to present his case.
Katsav has refused to step down during the months of investigation against him, saying he was the victim of a "witch-hunt".
But Israeli media, politicians and the public were nearly unanimous in their opinion that Katsav should go.
"Someone should explain to the honoured president that he should go home," wrote the second-largest daily, Maariv.
"Release his grasp on the trappings of power, pack his bags and take his leave of the president's residence in Jerusalem as quickly as possible."
Yossi Beilin, leader of the left-wing Meretz Party said: "He should resign as he has no right to leave us in this situation.
"As a society, we have the right to tell him that he is no longer our president and that his portrait can no longer be hung in schools."
Guidon Saar, the leader of the right-wing Likud opposition party, said: "The president must resign. Period. And I hope that he will take such a decision within the upcoming hours. If not, the ball will be in Knesset's court, which should fire him."
A poll published in Yediot showed that 79 per cent of Israelis had little or no confidence in the Iranian-born Katsav, who was elected by MPs in the Knesset in 2000.
Katsav is due to be indicted with raping an employee at the tourism ministry where he held the top post in the late 1990s. He will face separate charges of sexually harassing three other employees at the presidential residence.
He also faces charges of offering "dozens of silver cups" as gifts while serving as president and of obstructing the investigations into his activities, the ministry said.
He faces the prospect of becoming Israel's second consecutive president forced out by scandal.
His predecessor, the late Ezer Weizman, was forced to resign in 2000 after allegations he received around $450,000 as "gifts" from French millionaire Edouard Saroussi in the 1980s, when Weizman was an MP and minister.