The 1999 elections will be the first time Israelis have had more than two competing candidates. If no one takes more than 50 per cent of the vote, a second ballot will follow on 1 June.
The three main contenders are: Benjamin Netanyahu, the Likud incumbent whose coalition of seven right-wing and religious parties has disintegrated after only two-and-a-half years; Ehud Barak, Labour opposition leader, a former chief of staff and Israel's most decorated warrior; and Amnon Shahak, another top general who plans to run at the head of a centre party.
The opinion polls put Mr Shahak ahead in a straight contest with either of the other two, but trailing both of the other front runners in a three- sided race. In an attempt to win over so-called oriental Jewish voters, Mr Barak has recruited David Levy, the Moroccan-born former Likud foreign minister, to his cause.
The Likud and Labour party machines hope that by stretching the campaign to five months they are giving Mr Shahak enough time to make mistakes. Although he retired as chief of staff in the summer, he officially hung up his uniform only last week. He has yet to announce the name of his new party, its programme or its other members.
Both the main parties fear his disruptive effect. The Likud is smearing him as a "leftist", while Labour has condemned him for splitting the left- wing vote and trying to parachute straight from 40 years in the army into the top spot in politics.
"Decorated with ranks and medals though he may be, Shahak is a man in his mid-fifties who has not lived even one day as an ordinary citizen," a former Labour minister, Yossi Beilin, wrote in The Jerusalem Post. "While I salute him, I am not prepared to take the risk, just as no one would be prepared to be a passenger in an aircraft that I was piloting before I had learnt to fly."
Mr Barak has not yet given up hope of persuading his former army deputy to join him as Labour's prospective minister of defence, but Mr Shahak seems determined to win on his own. Although he shares Labour's commitment to the peace process with the Palestinians, he is not convinced that Labour under Mr Barak can make it.
Three Likud rebels have announced they are challenging Mr Netanyahu. They are Dan Meridor, who resigned 18 months ago as finance minister; Benny Begin, son of the party's founder and former prime minister Menachem Begin; and Uzi Landau, chairman of the parliamentary foreign affairs and defence committee.
Mr Meridor says he will run at the head of a new centre party. He represents the pragmatic right, which recognises that the Oslo and Wye agreements with the Palestinians have changed the political map. "There has to be a compromise," he argues, "but where we draw the demarcation line is open to negotiation."
His main quarrel with Mr Netanyahu is over his leadership style. "While facing the most difficult and important negotiations in our history," he says, "we come to the table with a leadership that doesn't have an ounce of credibility left. We are represented by someone nobody believes in."
Mr Meridor would like to run in harness with his fellow centrist Mr Shahak, but neither has so far conceded the number one position to the other. They share a reputation for decency and a hatred of Mr Netanyahu.
Benny Begin, who resigned as science minister in protest at the January 1997 withdrawal from the West Bank city of Hebron, is challenging Mr Netanyahu from the right. He is still waving his father's banner for a "Greater Israel" and will campaign on a platform of opposition to the Oslo accord. His chances are slim.
Uzi Landau, another unreconstructed hardliner, is running against Mr Netanyahu for the Likud leadership. The party's 3,000-member central committee will choose its candidate for prime minister on 25 January. It is expected to adopt Mr Netanyahu again.
Two disaffected Likud ministers are also weighing their options, either to run against Mr Netanyahu or to join a Shahak-Meridor centre party. They are the Defence Minister, Yitzhak Mordechai, who wants to accelerate the peace process, and the Communications Minister, Limor Livnat, the only woman in the cabinet, who wants to slow it down.
An unexpected contender hovering on the horizon is the recently appointed Foreign Minister, Ariel Sharon, at 70 another old soldier, who said enigmatically on Monday that "if the circumstances were right" he would not rule himself out. Mr Sharon is keeping his powder dry in case Mr Netanyahu's campaign falls apart.
THE RACE FOR PRIME MINISTER
Failed to get necessary support over Wye Accord, but is a skilled and devious campaigner who will fight an aggressive campaign
Party: Likud Chances: Down in polls but don't write him off
Israel's most decorated warrior and a firm supporter of the peace process. Is standing on a platform of national reconciliation
Chances: Good, but still has to prove himself
A political novice who has spent most of his life in uniform. Personal charisma may not be enough
Party: Doesn't yet have a party; a centrist
Chances: Sporting - a serious contender
Pragmatic right-winger who is a realist on the peace process. He argues that there is no going back. Wants to run with Shahak
Party: Likud defector, now a centrist
Son of Menachem. Believes Israel should control all Israel's biblical territories. Will challenge Netanyahu from the right
Party: Likud defector
Chances: None, but could split the right
Senior backbencher; an unreconstructed hardliner and Likud traditionalist who will challenge Netanyahu from within the party
Former hard-driving general, Defence Minister during the Lebanese war. Is propping up Netanyahu, but could step in if Bibi stumbles
Chances: Still hovering as an alternative to Netanyahu
Rough-hewn former chief of staff; his party is really a personal vehicle for his own right-wing nationalist and secularist agenda