BOEHLEN, GERMANY -- He preaches a depressing message and he knows it. But Oskar Lafontaine, the Social Democrat who is challenging Helmut Kohl to become chancellor of the united Germany, insists the truth is that times are going to get tougher even if the voters do not like to hear it.

"It's hard to tell people who struggled for decades under an oppressive system that tomorrow will not bring deliverance," Lafontaine said in an interview as he campaigned for Sunday's election, "but if one wants to stick to the truth, one must say there will be big problems for a number of years to come" before east Germans can attain the Western living standard they crave.

Kohl, the Christian Democratic chancellor who surprised even his supporters by uniting the two Germanys in a smooth 11 months, meanwhile, celebrates a revived and growing nation and that is what crowds, particularly in the east, do want to hear.

Yet Lafontaine stays on the road, winning votes by the hundreds, sometimes by the dozens.

Here he is in a foul-smelling chemical complex in the southeastern state of Saxony, trying to persuade east German workers that the colossal environmental and economic folly of the Communist system cannot be fixed as quickly as Kohl says it can.

"You were promised by the chancellor that the Western investors would come after the March elections, and then after you got the Western mark in July, and then after unification in October, and now they say the investors will come after the elections," Lafontaine said. "But it's not even so simple that if the Social Democrats win, investors will come. That's all nonsense."

The workers, their faces streaked with dirt and sweat, still wearing their Communist-issue blue overalls, began to nod.

"No investor comes out of patriotic feelings," Lafontaine continued. "They come only when they can make money. And they can only make money if the state provides the infrastructure: roads, power, telephone connections and educated, trained workers -- you.

"That costs money. Look at America. President Bush promised no new taxes. 'Read my lips. I promise.' And after the elections, new taxes. It will happen."

This is Kohl country, the bedrock of the historic March vote in which East Germans made their choice clear -- they wanted unification, the Western system, everything they'd seen on West German TV for all their lives. But now Lafontaine had them laughing, clapping and even saying they will vote for him.

It is a drop in the bucket. There are only about 60 people in the chemical works cafeteria. Thousands work here, but this day, unknown to Lafontaine's advance men, turned out to be a short workday -- the euphemism for the virtual state of unemployment in which many east Germans now find themselves. Told to take off one, two or three days a week, the workers are still listed by the government as employed, but they have nothing to do and not enough money to pay the ever-rising costs of living in the new Germany.

"He speaks the truth," said Heidrun Schleisch, a forklift driver who listened and found herself converted. "But the people don't want to hear the truth. They want to believe it's going to be good for the first time in 40 years. We're so fearful that we're losing our jobs. I just want to know the reality finally, after 40 years of lies."

On his campaign train to the next stop, a rally of 700 in the town of Aue, Lafontaine conceded that Kohl's message has a huge advantage. "We are in an extraordinary situation due to . . . German unity," he remarked in the interview. "If one thinks about how the people are reacting now, especially in the former East Germany, hope plays a big role. This is a favorable starting point for the government, less favorable for us."

Lafontaine, who led Kohl in polls by a wide margin in January, now trails 53 to 34 in the latest poll, issued Wednesday by the Allensbach Institute. He has not thrown in the towel, at least not publicly. But Helmut Schmidt, the Social Democrats' last chancellor, has. He said in a Dutch newspaper interview this week that "Lafontaine will not win. And he deserves to lose." Schmidt was slapped on the wrist by his party, but he said publicly what most Social Democrats say privately.

Until this summer, they say, Lafontaine appeared to be a good candidate at the wrong time -- a bright, blunt-spoken Social Democrat who gets along with business people but seems too slick and even decadent for the new eastern voters. Instead, party insiders say, Lafontaine turned out to be a poor candidate -- a political loner who ceded Kohl all the emotional advantages of unification and insisted on a relentless message of bad news.

Lafontaine, the 47-year-old prime minister of the state of Saarland on the French border, seems relaxed as he travels from rally to rally. There is none of the tension of a tight race. He is so straightforward that, although reporters are delighted, crowds seem not to know what to make of him.

In his stock speech, he admits that he appeared to oppose the quick route to German unity -- a position that did him irreparable damage in the eastern part of the country. He urges east Germans to seek the kind of friendship with Poles that west Germans achieved with the French -- an appeal that lands with a thud on audiences convinced that Poles are competing with them for scarce jobs.

Lafontaine even concedes that for a time this summer, he was not sure he really wanted to be chancellor -- a result of soul-searching after he was stabbed in the neck by a deranged woman in April.

In his double-breasted Italian suits and dark shirts, Lafontaine strikes many east Germans as something from one of the erudite talk shows that fill prime-time TV with chatter about wine, Spanish beach resorts and French novels.

The east Germans stare at Christa Mueller, the candidate's 34-year-old "life companion," and her spiky, white hair. Their eyes widen when they hear about his friendships with rock stars, or the French chef he hired for his Bonn office.

In his personal style and political philosophy, Lafontaine sees himself as a European more than a German. He pokes fun at Kohl's constant references to the reunited German "Fatherland."

Such positions endear Lafontaine to a young, socialist-minded sector of affluent western Germany. But in the east, where many are proud to be able to believe in their country for the first time, Lafontaine's reluctance to embrace such traditional concepts can be puzzling.

Kohl's Christian Democrats "will win because they stand for the big money and they're proud to be German," said Heidi Gurtler, a salesclerk who went to a Lafontaine rally in the eastern city of Chemnitz, where the Social Democrats had to stage a free circus to get 2,000 people out to hear Lafontaine.

In fact, far more than style separates the candidates. Kohl envisions private investment leading the way toward a better living standard in the east; Lafontaine favors government pump priming.

Both men effusively praise Soviet leader Mikhail Gorbachev, a sure-fire tactic for both western and eastern audiences. But Kohl also thanks the Americans for supporting unification. Lafontaine's only references to the United States are sharply critical -- he uses Bush as an example of a misleading politician, says America overstepped its economic limits, and calls for the removal of all U.S. nuclear weapons from the united Germany.

The challenger wins cheers with his call for an immediate end to the military exercises that have annoyed residents of both Germanys for decades.

And crowds seem to love his stance on the Persian Gulf crisis. While Kohl has said Germany must change its constitution to allow its troops to participate in international forces, Lafontaine said, "We say no to sending our troops around the world. We don't want the larger Germany to play world power."

On many issues -- the gulf crisis, the environment, the likelihood of a tax increase to pay for unification -- it is Lafontaine's views and not Kohl's that match what Germans tell pollsters they believe.

But things are going well for much of Germany now, and the outcome appears to be as close to a sure thing as you get in politics. That leaves Lafontaine thinking about the next time, and it leaves his staff more than a little depressed. "People don't like to hear the truth," said aide Ruth Meiss.