The film-maker made an award-winning documentary last year -- "Rabin, The Last Day" -- about the last 24 hours of the murdered leader's life.
The former general was shot by a Jewish extremist opposed to the Oslo peace accords with the Palestinians, for which Rabin had won the Nobel peace prize.
But in "Yitzhak Rabin, Chronicle of an Assassination" -- premiering this week at the Avignon festival in France -- Gitai recounts the killing through the eyes of his widow.
And in a twist in keeping with her own tireless efforts for peace, Leah Rabin is played by both Franco-Israeli star Sarah Adler and a Palestinian actress Hiam Abbass.
Using long interviews he conducted with Leah Rabin before she died in 2000, Gitai shows how the killing was "both a personal tragedy and an unprecedented historic disaster for the country".
Rabin was murdered by a lone gunman as he got into his car after a peace rally in Tel Aviv.
In one chilling scene, Leah Rabin tells how the night before the killing a group of 50 far-right activists surrounded their home.
Among them was her husband's killer, Yigal Amir.
'Hang by the heels'
Alone inside, she listened as they threatened to hang her "by the heels next to your husband like Mussolini and his mistress" in a reference to the Italian dictator and his lover, whose corpses were displayed in a Milan square in the last days of World War II.
In both the play and the film, Gitai blames the killing on an atmosphere of hate he claims was whipped up by the Israeli right including by the future prime minister, Benjamin Netanyahu.
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He described his documentary as a "commission of inquiry" into the murder.
"(The) official one mostly investigated the security failures of the police and security services but never asked why," he told AFP.
"His murder came at the end of a hate campaign led by hallucinating rabbis, settlers who were against the withdrawal from territories, and the parliamentary right, led by the Likud (party), already then headed by Netanyahu, who wanted to destabilise Rabin's Labour government," he said.
Gitai, who was wounded in the 1973 Yom Kippur war when his helicopter was hit by a Syrian missile, described Rabin as a "patriot and a peacemaker" and said it was vital that the memory of what he was doing is kept alive.
The play also reveals how Rabin hesitated about going to the rally, fearing that if there wasn't a huge crowd his presence might weaken the peace movement.
As "Rabin, The Last Day" outlines, in the months before his assassination, an ugly mood had developed, with virulent speeches from politicians such as Netanyahu at rallies against the Oslo accords. At one of them, Rabin was depicted in a Nazi uniform.
Leah Rabin accused Netanyahu of inciting hatred against her husband, saying, "I will never forgive him."
Gitai, best know for his films "Kadosh" and "Kippur", is also staging a travelling exhibition about Rabin's murder in Avignon, and the play will later transfer to the Lincoln Center in New York.
Two decades after Rabin's death, he insisted that "the only alternative to the those now in power is this dead man.
"I know I am touching on a very sensitive subject in Israeli. Only a few days ago at the Jerusalem festival the Minister of Culture (Miri Regev) accused Israeli artists of being Trojan horses of the enemy," Gitai said.
As the Israel government defies international condemnation of renewed settlement building on the West Bank, Gitai said "we must talk about (Rabin's) ideas of moderation, reconciliation and moves towards the other" rather than the maximalist mentality that dominates the "Middle East with every group out for their own interests".
Gitai said this "civic" message is not just for his own troubled region.
"Whipping up hate has become a good way of getting elected all over the world right now when you look at Donald Trump in the United States, and what is happening in Europe, Israel, and the Middle East."