West Germany's Franz Josef Strauss has long managed to collect nasty political epithets about himself the way a hairy hound in the woods catches burrs.

With a couple of weeks to go before the big campaign speeches begin in Germany's federal elections, the conservative challenger to Chancellor Helmut Schmidt is trailing badly in the polls, defeated so far by his old image as a dangerously excitable national security risk.

Determined not to go down without a last lunge of bullishness, Strauss is preparing to lash out at Schmidt with a ferocity likely to make this election the most confrontational in the 31-year history of the German Federal Republic.

On the surface, there are some parallels between the campaigns of Strauss and U.s. rEpublican presidential candidate Ronald Reagan. Both men are plagued by hard-to-shake images of ultraconservatism and tend to be associated by some voters with the spectre of World War III.

In West Germany, this is a particular liability, since German sensitivity to the thought of war is high.

Schmidt's Social Democratic Party and its friends have skillfully played on the fear of Strauss, running a scare campaign against him and leaving him with a dilemma.

If he responds in kind to the attack, he seems to confirm the charge of irresponsibility. But if he does not, he is branded by his Christian Social-Christian Democratic supporters as an ineffective campaigner.

In the aftermath of the Soviet invasion of Afghanistan, which raised in Germany fears of a new world war, Strauss tried to don the mantle of statesman. He showed an uncharacteristic reserve in his comments on Schmidt's tempered handling of East-West relations.

But the strategy did not work, mainly because neither the news media nor the voters in state elections in the spring believed a change had come over Strauss. Recently the Bavarian prime minister has grown more vituperative in his criticism of Bonn policy and is zeroing in on Schmidt.

"We had a discussion over whether it would be better to hit Schmidt personally or just the [party]," Godel Rosenberg, a Strauss campaign aide, explained in an interview. "We decided we had to hit Schmidt because he is chancellor and is responsible for policy in this country. I think Strauss will be hitting hard."

He has waged his fight on two planks. On foreign policy, without accusing Schmidt outright of disloyalty to Washington or subservience to Moscow, Strauss has implied that the chancellor is an unreliable ally of the United States who is forced by the left wing of his party to be soft on the Soviets and weak in defense of the West.

On the economic policy, Strauss has highlighted the size of the federal debt and pointed to creeping inflation and unemployment in West Germany.

But although Strauss does try to talk about the issues, this federal election has turned into a contest of personalities as never before in West Germany. In general, German elections tend to resemble barefisted boxing matches, and this one is shaping up as the meanest.

It has already reached a vicious pitch, with both major parties putting out scathing posters, outrageous cartoons and suggestive movies about the leading candidates for the chancellorship.

Some examples:

A poster in Bremen showed Strauss in Nazi uniform draped with a blood-spattered butcher's apron and holding a meat cleaver. The caption read, "What speaks in favor of Strauss is that he knows his business."

A communist handbill in Erlangen that depicted Strauss in lederhosen, with machine gun in hand, bore the slogan, "Strauss, the Hitler of today."

A poster in a Stuttgart bookstore window declared, "Anyone who votes for Strauss votes for reaction, fascism and war."

Such polemics have kept the courts busy weighing Strauss' personal rights against the constitutionally guaranteed freedom of opinion. The posters were allowed, but a Nuremberg court banned the communist handbill.

It held that while "individuals or groups must put up with shocking hurtful and unjust views and criticisms -- and a candidate for the chancellorship is naturally the main butt of such attacks by political opponents -- this is not an open invitation to engage in unbridled defamation and polemics. A politician's honor must also be protected, though the criteria applied here differ from those applied to other individuals."

"In this case," concluded the court, "the honor of Franz Josef Strauss has been so grossly besmirched that his right of protection outweighs the freedom of speech."

To take the load off the courts, Germany's political parties formed an indepenent commission of official campaign referees. But the only sanction the group can apply against overly zealous pamphleteers is publicly to name them.

The Strauss forces have engaged in some mudslinging themselves. A campaign poster being distributed by his party reads:

"Germans, do you know who is behind the anti-Strauss compaigns? East German-financed journalists, bad-check writers, pot-smokers, friends of terrorists, communists and, unfortunately, also the Social Democrats. Stop this leftist popular front."

In a personal swipe at Schmidt, the opposition recently produced a film that portrays the cancellor as a gross opportunitist in the keep of this leftist front. The film, a 35-minute show entitled "The End of a Legend" and available on video cassette, is in reaction to "Der Kandidat," a highly polemic quasi-documentary that attempts to cast Strauss to the right of the Nazis.

It all goes as planned, Strauss and Schmidt will actually face each other only once during the course of the formal campaign, in a televised debate scheduled three days before the election.