NEWS ANALYSIS : Stunning Comeback Seen for Peres : Israel: The Labor Party’s unpopular leader emerges as the prime candidate to form a new government.

Shimon Peres is widely believed to be Israel’s least popular major politician. He has failed to lead his Labor Party to victory in four straight elections, and yet, by way of a laborious process that begins today, he stands a good chance of becoming the country’s next prime minister.

If Peres succeeds, his would be one of the most extraordinary comebacks in Israeli political history. A few months ago, Peres was considered to be a washed-up, somewhat pompous figure clinging to leadership of the Labor Party only until the next elections, when someone else would lead Labor out of the wilderness. Now, he is not only poised to rule but eager to take Israel into historic peace talks with Palestinian adversaries.

To reach that point, Peres must first be nominated by President Chaim Herzog as the candidate most capable of lining up a majority of votes in the Knesset, or Parliament, to support a government. Herzog will begin to canvass an array of party leaders today to see who enjoys widest support.

If it is Peres, he must then forge a coalition from diverse political forces: his own center-left Labor Party, secular and socialist groups that are further to the left, religious parties and parties representing Israel’s Arab population. Most are barely on speaking terms.

He might invite the Likud Party of caretaker Prime Minister Yitzhak Shamir into a renewed role.

The mathematics are simple, even if the process is not: Peres must find parties with a total of 22 seats to add to Labor’s own 39 and gain a majority in the 120-member Parliament. Ministries and money will be offered to parties and causes in a wide-open marketplace.

“It seems to be Shimon Peres. He should be able to put together a coalition of 65 or 66 votes. That’s the best bet at this point,” said Daniel Ben-Elizar, a political analyst in Jerusalem.

Peres’ chance came with the fall of the 15-month-old coalition government led by Shamir, the tottering head of rightist Likud. The government, an uneasy Likud-Labor partnership, fell over its inability to act on peace proposals.

Peres served as prime minister from 1984 to 1986 in a rotation agreement with Shamir when Labor and Likud first joined in a unity government in the wake of the Lebanon war. He won a measure of praise for bringing inflation under control, but he also earned a certain image as being evasive and untrustworthy--something of an “Israeli Nixon.”

In popularity polls taken since the 1988 general elections, when Labor came in second to Likud, Peres has always run far behind not only Shamir but also Labor Party rival Yitzhak Rabin, lately the defense minister.

Labor’s junior status in the recently fallen coalition had forced Peres, 66, off center stage into the role of finance minister. Only frequent trips to world capitals and his expressed interest in peace talks reminded the public of Peres’ larger ambitions.

He used his position in the Finance Ministry to maintain his strength in Labor and bolster his cause with religious parties, whose black-clad leaders made frequent visits to the Finance Ministry.

Peres funneled money into deteriorating Labor strongholds in industrial unions and on communal kibbutz farms. For the religious, he provided funds for education--including a $50-million aid supplement approved just last month and a $2.5-million check signed just before Shamir fell.

“The finance minister has been preparing well for setting up the next government,” a Foreign Ministry official commented dryly.

For the past several weeks, Peres carried on openly secret negotiations with religious party leaders to try to persuade them to join a Labor government if Shamir fell. To the Sephardic Shas party, which controls six seats, he offered movement on peace talks, a growing concern in the religious group.

At least one other religious party, Agudat Israel, has shown interest in a Peres government, more out of spite than conviction. Agudat is angry at Shamir for having reneged on an agreement to let Orthodox Jewish rabbis set standards for determining an individual’s Jewishness. Shamir dropped the pledge when, having enticed Labor to join the government that recently collapsed, he no longer needed Agudat’s help to form a coalition.