Weizman is stepping down three years before his second five-year term ends following an investigation into an alleged gift-taking scandal.

Attorney General Elyakim Rubinstein decided last week not to press criminal charges against Weizman but accused him of ethical violations. By resigning, Weizman is avoiding a potential impeachment.

Kastav was named earlier this week as the Likud's candidate to replace Weizman, and Labor Party-led One Israel was expected to bring the Peres nomination before its central committee today. Prime Minister Ehud Barak has already announced his support for Peres.

It is no secret that Barak and Peres have disdain for each other. Barak has apprehensions that if Peres becomes president, he would double as a pesky shadow premier.

But political observers said that Barak knows he can't oppose Peres since the former prime minister controls much of the Labor Party machine. Peres is currently regional cooperation minister in Barak's government.

Barak supposedly would have preferred to team up with the Likud leader Ariel Sharon to jointly nominate non-partisan Meir Shamgar for the presidency.

Only if Labor gets extremely anxious about Peres' chances, would Barak get a faint green light to switch to the Shamgar track.

But Likud has never successfully fielded a candidate for president and Katsav chances appear dim.

The only question is how many undeclared enemies Peres has. It's not inconceivable that some colleagues in One Israel may betray him.

Others, like Foreign Minister David Levy, have declined to state whether they will back Peres. Levy has been wary of Peres' ambitions in the foreign policy sphere and has privately accused him of treading on his toes. There is no love lost between them.

But as for now, no candidate has come forward who stands a chance of beating Peres.