Labor statistics show that foreign-born workers account for all net gains in U.S. employment in the past seven years, according to a group that advocates low immigration.

The Center for Immigration Studies issued a report Friday that found 1.5 million fewer U.S.-born workers employed in 2014 than prior to the recession in 2007. Foreign-born employment for both legal and illegal immigrants increased by more than 2 million workers during the same time period.

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The data, which CIS obtained from the Bureau of Labor Statistics, is evidence that native-born workers could have a harder time finding jobs under President Obama’s plan to allow more than 5 million illegal immigrants to obtain work permits, CIS officials said.

“If we continue to allow in new immigration at the current pace or choose to increase the immigration level it will be even more difficult for the native-born to make back the ground they have lost in the labor market,” the report’s authors, Steven A. Camarota and Karen Zeigler, wrote.

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U.S. employment numbers have been on the rebound for months.

The U.S. economy added 321,000 jobs in November, one of the strongest gains in three years.

The unemployment rate has steadily fallen and is now 5.8 percent, the lowest level since June 2008.

But Camarota and Zeigler say that employment numbers for U.S.-born workers has still not returned to pre-recession levels, while it returned to pre-recession levels for immigrant workers in 2012 “and has continued to climb.”

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Overall, the number of U.S.-born workers fell from 124,014 million in November 2007 to 122,558 million in November 2014. Foreign-born workers, who make up 17 percent of the workforce, increased from 23,104 million to 25,108 million in the same time period.

The BLS figures showed that 11 million fewer U.S.-born workers are in the labor force now compared to 2007, and that figure has not improved in the last year.

Camarota and Zeigler say the numbers show there is no labor shortage, “even as many members of Congress and the president continue to support efforts to increase the level of immigration.”

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Immigration reform advocates, however, argue that while unemployment remains high in some places, foreign-born workers are more willing to take on jobs U.S.-born workers reject in the service sector, construction and farm fields, for example.

A May 22 report issued by the BLS found that the 2013 unemployment rate for foreign-born workers was 6.9 percent, compared to a 7.5 percent jobless rate for U.S.-born workers.

Hispanics made up nearly 48 percent of the foreign-born labor force in 2013, the BLS found.

Foreign-born workers, the agency said, were more likely to be employed in service occupations, rather than “management, professional and related occupations and in sales and office occupations.”

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Congress in 2015 is likely to take on immigration reform in a piecemeal approach, rather than one comprehensive package, according to GOP lawmakers who will run both the House and Senate.

While border security will be a primary focus, lawmakers may also consider increasing visas for both low- and highly-skilled workers. They may also debate an expanded program for immigrant agricultural workers, known as a guest worker program, as well as a plan to legalize the 11 million people now living here illegally.

The issue has divided the GOP, with some conservatives arguing the move will depress wages and raise unemployment rates for U.S.-born workers and put an unmanageable strain on federal subsidies.