Originally from the area around Erfurt in eastern Germany, Mr. Hintermeier has spent 15 years as a temporary worker, going wherever the jobs are.

“You’re doing the same work for less pay,” said Mr. Hintermeier, who earns about 9 euros, or almost $13, an hour. That is about $2.86 an hour less than the average for eastern Germany, and $7.16 to $8.59 less than in wealthier regions of the country, where Mr. Hintermeier often works.

On top of that, “there aren’t many opportunities to develop,” he complained. And he said he often encountered resentment from co-workers who consider him low-cost competition.

Mr. Hintermeier is one of nearly a million temporary workers, almost 3 percent of the work force, who in recent years have given German companies much more flexibility than before. Temporary employment played a critical role in helping Germany weather the 2009 downturn, as employers were able to quickly respond to ebbing demand by reducing payrolls.

But an increasingly vocal group of critics say that the loosening of regulations in 2003 allowing companies to hire temporary workers has created a vast cohort of poorly paid, poorly treated employees with slim chances of obtaining permanent jobs. With the economy surging once again, unions are lobbying for legislative changes and raising the issue of temporary workers at contract talks.

“Temporary work has enabled a shadow labor market,” Berthold Huber, chairman of the IG Metall labor union, said at a news conference in Frankfurt last week. “That is intolerable.”

Temporary employment, already a boom industry in Europe, is about to get more support when the last restrictions on labor mobility among European Union countries fall away on May 1 — coincidentally the day when Europe celebrates the labor movement. Temporary-employment agencies will then be able to recruit workers in low-wage countries like Poland for jobs in Germany and elsewhere.

“That will certainly raise the pressure,” said Sandra Siebenhüter, who has studied temporary work for the Otto Brenner Foundation, a research organization in Frankfurt that is financially supported by IG Metall.

While there are plenty of anecdotes about temporary workers who are receiving worse deals than permanent employees, the loosening of Germany’s traditionally rigid labor market has been crucial in preventing at least some companies from shipping production abroad.

“Our global competitiveness would deteriorate if we were unable to use the instrument of temporary employment,” Bayerische Motoren Werke, the maker of BMW vehicles, said in a statement, noting that 75 percent of its work force was in Germany, while 80 percent of its car and motorcycle sales were abroad.

At the heart of the debate is the question of whether a temporary, lower-wage job is better than no job at all.

The rise of temporary labor has contributed to a plunge in German joblessness. The unemployment rate has fallen to just above 7 percent, or 3.2 million people, from nearly 12 percent in 2005, or almost 5 million people.

Temporary employment agencies have soaked up a large proportion of those jobless people, many of whom lack training. The industry draws two-thirds of its new employees from the ranks of the unemployed, according to a study by the German Federal Employment Agency.

Randstad Holding, a global temporary-employment agency based outside Amsterdam, has created 50,000 jobs in Germany over the last two years, said Ben Noteboom, Randstad’s chief executive. Most of the people hired had been jobless, he said.

“In the past, staffing was difficult legally,” Mr. Noteboom said. “The moment it changed, the market started to boom.”

He said that he was baffled by efforts to tighten restrictions on temporary hiring. Abuses by a few companies had turned public opinion against the industry, he said. “In Germany, we do see that there is more aggressive talk against our business,” Mr. Noteboom said. “I don’t know how many difficulties you want to create for your companies to stay in the country.”

In fact, Mr. Noteboom said, Germany still has some of the tightest protections anywhere for temporary workers. He said that he considered “temporary worker” a misnomer in the first place. In Germany, Randstad’s workers have the status of regular employees with full health and pension benefits. They are simply lent to other employers.

Article source: http://feeds.nytimes.com/click.phdo?i=3a62e983397857445cb7938fe7b0f675