West Germany's vitriolic election campaign drew to a stinging finale today with Chancellor Helmut Schmidt considered likely to win a new four-year term against conservative archrival Franz Josef Strauss.

Sunday, about 90 percent of West Germany's 42.8 million eligible voters are expected to go to the polls in a parliamentary election that national opinions surveys have consistently said should return Schmidt's left-liberal coalition with a comfortable lead.

Both Schmidt and Strauss chose final stops today that reflected the character of their campaigns. Schmidt spoke in Berlin, the divided city that stands as a symbol for Bonn's pursuit of cooperative relations with the Soviet Union and communist states of Eastern Europe.

At a party rally, Schmidt stressed the need to continue East-West talks on disarmament, a central plank of his Social Democratic Party.

"Those who want to get along, must make contacts," he declared. "This concerns especially the mutual control of arms, since the number of arms in Europe and the world is already too high and must be decreased on both sides."

Strauss, meanwhile, returned to his home state of Bavaria where, in the small town of Mittenwald amid the sort of southern German crowd who appreciate him most, he lashed out against the "bureaucratic socialism" of the Schmidt government and against "the destruction of the order of values" that he said had taken place in West Germany.

Throughout the campaign, the 65-year old Bavarian governor sought to present himself and his Christian Democratic Christian Social Union coalition as defender of West Germany's traditional values against the experiments in social and foreign polices undertaken during 11 years of Social Democratic rule.

One domestic policy, his major attacks were against Bonn's growing indebtedness and the government's controversial efforts to deal with terrorism. iOn foreign policy, he portrayed Schmidt as being in the keep of a "Moscow faction" within the Social Democratic Party and warned that the government's policy of detente could bring West Germany under Soviet influence.

But Strauss' mercurial, provocative personality managed during the campaign to eclipse the issues. Strauss provided an easy political target for Schmidt. The chancellor frequently attacked Strauss as lacking the control necessary to conduct West Germany's delicate foreign policy and keep international peace.

"You must see an end is put to this specter," Schmidt roared before a large crowd in Frankfurt last night. "We want him out of the internal political scene once and for all. He has polluted the air long enough."

Jumping on Strauss again today as a loud-mouthed demagogue who would pose a danger to peace in Europe if elected chancellor, Schmidt added. "A facility for good neighborly relations and for peace simply has not matured in the man."

The barbs are representative of the volly of insults and personal recriminations thrown back and forth between the major candidates during much of the campaign, culminating in a 3 1/2-hour televised debate Thursday night that was seen as imparting little information but lots of invective.

"A deep breath of relief goes now through the whole republic, a big sigh is now heard," wrote the Munich daily Suddeutsche Zeitung in a comment reflecting the disappointment with the campaign felt by many West Germans. "There is probably hardly anybody who could endure any longer what we had to hear in the past weeks."

Aside from the clash of dominant personalities in the campaign, the lack of discussion on the issues may also have reflected the fact that relatively few people profess to see much difference in platforms between the major parties, West Germany is among the world's most affluent and stable societies, and this development has contributed to the forging of a substantial political consensus on foreign and domestic policy.

While Strauss railed against the Schmidt government's pursuit of cooperation with the Soviets, he could hardly have suggested that Bonn retreat from its carefully crafted policy of detente in the middle of Europe. And while he attacked the government with some effort for increasing the national debt, his own coalition, which holds the majority in the upper house of the West German parliament, had to take some responsibility for it.

In a nation feeling increasingly self-assured largely as a result of its impressively strong economic performance, the confident, commanding Schmidt has appeared a natural reflection of the public mood. He has been riding a popularity crest for a number of months. His primary campaign message was to promise a continuation of the same policies that has brought West Germany relative stability and prosperity.

The chief elements of suspense in the election center of two things. First, whether the Social Democrats will be able to win enough seats to pass the Christian Democrats as holding the largest parliamentary bloc, second, how well the Free Democrat Party, the Social Democrat's junior coalition partner, does in the vote.

Once considered in danger of falling below the 5 percent mark necessary to be represented in the West German lower house, the Free Democrats are now expected to score around 8 percent -- a tribute largely to the campaigning skills of party chief Hans-Dietich Genscher, also Schmidt's foreign minister.

Genscher is regarded widely as having fought the fairest campaign, and his popularity together with Schmidt's could end up multiplying several times the 10-seat majority their coalition now hold of the 496 lower house seats to be chosen.

Much depends on the size of the voter turnout. While traditionally high-running above 85 percent in elections since 1953 -- there is some concern among Social Democrats about the number of West Germany's 3.6 million young voters who will go to the polls. A good proportion of the youth vote has traditionally been claimed by the Social Democrats.

One additional worry is the amount of confusion voters will experience in reading the ballot. On it, West Germans are asked to vote twice, once for the candidate in the local constituency and a second time for a political party.

This second vote is the more significant one, in that it determines the final balance of power in the lower house and, effectively, who will be chancellor. But recent polls have shown that a majority of voters do not understand the value of each vote.