If it seems that Mr Peres was always present as the great dramas of Israel's short history unfolded, it is because he always was. From chief weapons purchaser and recruiter in Israel's 1948 independence war, he went on to serve as head of every senior department of state.

With his distinguished silver hair and impeccable dress sense, coupled with the demeanour and vitality of a man two decades his junior, 83-year-old Mr Peres has become the acceptable face of Israel even in those international circles that are most critical of his country's policies.

As Nobel prize winner, founder of the Peres Centre for Peace and architect of the Oslo peace process, the Polish-born Peres presents to the outside world, in guttural but fluent English and French, an image of reason and moderation.

It is perhaps not surprising that the respect he enjoys abroad is not always reflected by his standing in the hothouse of Israeli politics. At home, he is saddled with a reputation for duplicity and scheming.

A sceptical press notes his seeming inability to bow out gracefully as he approaches the middle of his ninth decade.

A satirical column in the daily Maariv suggested mischievously that the presidency could be the first of future glories. "The presidency could be a great springboard for your career. Who knows what the future has in store for you? After eight years of a successful presidency, you may be able to run for chairman of a major party, win, and then go on to be prime minister."

The sting was in the tail. Although Mr Peres has twice served as prime minister, he has never been elected to the post in his own right. He retained the vice-premiership after general elections last year, having dropped his 38-year allegiance to the Labour party he helped to found in order to join the centrist Kadima.

He crossed the Knesset floor within a month of failing to hold the Labour leadership against a challenge from Amir Peretz, a firebrand union leader whose own leadership has since foundered in the wake of last year's Lebanon war.

Mr Peres should perhaps have been inured to surprise defeats. He succeeded to the premiership when Yitzhak Rabin, prime minister, was assassinated in 1995, but narrowly lost to Likud's Benjamin Netanyahu in Israel's first direct elections for prime minister the following year.

In the last presidential contest in 2000, he lost to Moshe Katsav in a 63-57 vote in the Knesset.

Israeli parliamentarians have had cause to rue their choice of Mr Katsav, who was this year obliged to relinquish his largely ceremonial role in the face of a sex scandal and a pending criminal indictment that may include charges of rape. In the circumstances, Mr Peres certainly qualifies as a safer pair of hands.

However, he is not, according to aides, taking his election for granted. He faces a rightwing challenge from Reuven Rivlin, the hawkish former Likud speaker of the Knesset, whose supporters have been highlighting Mr Peres's close association with the hated Oslo peace accords.

A third candidate, Labour's Colette Avital, contributed to Mr Peres's reputation for political skulduggery when she claimed his close aides had been pressing her to withdraw from the race.

Mr Peres has the support of Ehud Olmert, although the backing of a prime minister with Israel's lowest-ever popularity ratings might prove to be a poisoned chalice.

His prospects were boosted last week when the Council of Torah Sages of the ultra-orthodox Shas party ordered its 12 parliamentarians to vote for him in this week's election in "recognition of his good work for Judaism".

It is one of the many constituencies that Mr Peres has skilfully cultivated in six decades in politics in which he became associated with big ideas, some of which came to fruition.

He sponsored the growth of a domestic armaments industry and persuaded France to co-operate in Israel's nuclear reactor programme. He was at times an enthusiastic supporter of Israeli settlement in the occupied Palestinian territories, although his sponsorship of the peace process involved the inevitable surrender of land.

His concept of a Middle East common market that would grow out of the peace accords remains an unfulfilled dream.

If he is denied the presidency in Wednesday's Knesset vote, it need not be the end of the road. It is difficult not to see him continuing as an unofficial ambassador for Israel even if he did decide to surrender public office.

Perhaps no one better embraces the sentiment once expressed by his equally famous cousin, the American actress Lauren Bacall: "I am not a has-been. I am a will-be."