A bill that would require U.S. businesses to use a government database to verify that new workers are in the country legally is giving the agriculture industry a slight break.

The Legal Workforce Act would give the agriculture industry, where labor, industry and government officials say the vast majority of workers are illegal, three years to screen all new hires to make sure they are eligible to work in the U.S. The remaining employers would have two years to comply.

"We recognize that the agriculture industry is a special situation and we need to treat them differently," the bill's sponsor, Rep. Lamar Smith, R-Texas, said.

Farmers have complained that the requirement would decimate their work force, and that Americans are unwilling to take the back-breaking, low-paying jobs picking crops by hand.

Smith introduced the bill Tuesday, about three weeks after the Supreme Court upheld an employer sanction law in Arizona that required businesses to use E-Verify or face losing their business licenses.

Smith's bill would apply only to new hires. It also would pre-empt any state laws and end the use of paper I-9 forms that businesses currently use to show that they've verified that their workers are legally eligible to hold a job in the U.S.

E-Verify long has been considered among the only immigration-related bills likely to pass a divided Congress this year, but some had worried that making the system's use mandatory could destroy the agriculture industry.

Smith said he doesn't consider the bill a piece of immigration legislation, rather a jobs bill that eventually would move the nearly 8 million illegal workers out of the American workforce.

Agriculture industry officials have said the current system to hire legal immigrant workers -- the H-2A visa program -- is too cumbersome, time consuming and costly to use effectively.

"It has never been a great program or easy to work with," said Cathleen Enright, vice president of federal government affairs for the Western Growers Association. "It's an unbelievably crushing program."

She and others, including Rep. Zoe Lofgren, a California Democrat from an agriculture-rich industry, have said they fear a mandatory E-Verify program would cripple the industry.

But Smith insisted that postponing full implementation for agriculture businesses for three years would give the industry plenty of time to legalize its workforce and avoid economic calamity.

"We give them a three year phase in," Smith said, adding that other industries would be phased into the program in six month intervals over two years. "But more importantly than that, we do not require them to check current employees that return to work. That allows them to build on their current workforce and every year transition into a more legal workforce."