A new study finds the economic crisis is hitting a key engine of growth - foreign migrants.  The report by the Paris-based Organization for Economic Cooperation and Development warns this trend could hurt richer and poorer nations.  

Immigrants are an important part of the labor market in richer nations - making up about 10 percent of the labor force and taking jobs native workers cannot or do not want to fill.  But a new study finds the economic downturn means hard times for these immigrants, as unemployment rises and governments increasingly favor native workers.

Released Tuesday by the Organization for Economic Cooperation and Development, the report also predicts the crisis will lead to a drop in immigration to OECD countries for the first time since the 1980s.

Thomas Liebig is an economist at the OECD.

"In many, most, OECD countries, unemployment (among migrants) is rising much more rapidly than among native populations," Liebig said.  "And there are a number of reasons.  First, all migrants are more often represented in sectors such as construction, hotel and gastronomy - and also manufacturing - which are more cyclical.  They are much more hit by the downturn."

Liebig says migrant workers also tend to hold part-time jobs that demand unskilled labor, which again makes them vulnerable.

Migrants working in the 30-OECD nations come from all over the world - in the case of the United States, many hail from Latin America.  In western Europe, they come from Africa and eastern Europe.

Just a few years ago, they were a critical factor in the economic booms witnessed in Spain, Ireland and Britain.  And the money they sent back to their families in the form of remittances was also important to the economies of developing nations.

Almost one-in-10 immigrants working in Spain was unemployed during the first quarter of this year, for example, almost twice the unemployment rate of local workers.  Immigrants also face discrimination in their host countries, many of which are tightening their immigration policies.

But Liebig says that does not necessarily mean these migrants are going home.

"We still have the (economic) crisis in origin countries.  So financial incentive might not be sufficient to incite migrants to go back in a situation where they face even poorer working conditions in poorer nations," Liebig said.

The OECD is urging governments not to slam the door on migrants and to adopt fairer immigration policies because they will need foreign labor in the future when the economy picks up.