AS ISRAEL'S UNITY government falters at the brink of collapse, those on both sides of the political fence have eagerly rushed in to give it the final shove over the edge--into a chasm of national economic disaster and minority rule.

Israel's government officials, who have tenuously united the nation's two major political parties in a 19-month old coalition, are playing a frantic game of musical cabinet seats to salvage the unity coalition. It all began when Finance Minister Yitzhak Modai, engineer of the miraculous plan that tightened up Israel's inflation-racked economy, flung insults at Prime Minister Shimon Peres. Peres felt he had to respond; but if he dismissed Modai, the rightest Likud officials threatened to leave the coalition Cabinet.

Then, compromise Israeli style. Likud bloc leader and Foreign Minister Yitzhak Shamir volunteered to switch jobs with his Likud cohort Modai. Negotiator turned money man, and vice versa. Peres will save face by playing tough guy with Modai, Shamir will patch together the coalition until the rotation agreement lands him the premiership this October, Modai will stay in the Cabinet and assume what is said to be his dream job. Everbody's happy. Unless conniving politicos get their way, that is.

In a bid for personal power, Likudnik David Levy has been trying to sabotage the unity government. At last month's Herut party convention, which is the core of the Likud bloc, Levy formed an ad hoc alliance with Ariel Sharon to divert delegates' attention away from the agenda and undermine Shamir's leadership.

If Levy were to conquer the Likud camp, the guaranteed shift of the country's top position would be snatched away from any Likudnik, since the rotation agreement is dependent upon Shamir's heading the party. Now Levy is maneuvering to destroy the ministerial switcheroo agreement, since there is nothing in it for him.

And Laborites also are attempting to tear apart the coalition. Party leaders pressured Peres to use the Herut convention crisis as a pretext to dismantle the unity government and hold early elections. They have even initiated negotiations with small party leaders to test out their chances for a coalition without Likud.

BUT DESPITE THE dissatisfaction of conniving politicians, most Israelis would like to see the unity government continue. According a poll published in the country's main newspaper last week, seventy percent of Israelis want the coalition to stay in tact and the rotation agreement carried out. The public knows when they are getting a good deal.

With Modai at the helm, the unity government revitalized the inflation-racked country's economy. Israel implemented austere wage-price controls that trounced on the more than 400 percent inflation each year, lowering it to a bearable 20 percent. For the first time in a decade, 61 percent of the Israeli public approved of the government's economic policy, according to a poll by the Smith Research Center. Only the Labor-Likud combo can take credit for such effective fiscal policy.

The unity government has also succeeded in placing the parties with the most votes in the position with the most power. In the past the single party winning the most votes had to construct a coalition to form a majority among the parliament's 120 seats, with coalition-builders bending over backwards to appease the inflated demands of small party power brokers. One third of Israeli voters, those who chose the second largest party, were left in ineffectual opposition to the narrow coalition.

Take, for example, the case of the religious parties. Although only 20 percent of the nation's Jews adhere to orthodox practices and religious parties have won only 13 seats in the last two elections, the orthodox parties have controlled crucial swing votes necessary for narrow coalition building.

Both Labor and Likud have had to concede control over religious issues that inhibit the behavior of the largely secular nation, such as halting public transportation and the national airline on the Sabbath. Without the religious parties to form a Parliamentary majority, pre-unity governments were helpless: in 1976 the Labor Prime Minister Yitzhak Rabin had to resign in the aftermath of a tiff with Orthodox leaders about breaking the Sabbath.

In addition to curtailing the inordinate influence of tiny parties, the unity government has blocked any chance for a single large party to pour money into its favorite industries to pander to party supporters. While before the coalition the opposition could only watch powerlessly on the sidelines, Labor and Likud together have been able to check each other's spending.

If the goverment were to split up now and hold early elections, the contending parties would be averse to carrying out necessary budget cuts that would anger a portion of the electorate. According to Israeli economic experts, the gains of the last year's economic turn-around would be reversed. Subsidies for favored interests would rise in the quest for votes and the economy would return to the skyrocketing inflation of years past.

All the ills of a coalition break-up augment the probability that neither large party will receive enough new votes for a narrow coalition base anyway. Israel must keep the unity government intact. The strains of reluctant cooperation are hardly as threatening as a return to the futile antagonism of a single party government.