Two dozen House Republicans led by Judiciary Chairman Lamar Smith (R-Texas) are co-sponsoring legislation that would create an immigration amnesty. The legislation, the "Legal Workforce Act," would not, though, offer a true amnesty, under which unauthorized workers would be granted legal immigration status.

Call this proposal a "dirty" amnesty. Instead of offering legal status, the Legal Workforce Act promises that if unauthorized immigrants work in the fields, the U.S. government will just look the other way.

The Legal Workforce Act makes E-Verify, an electronic employment verification program, mandatory across the nation. E-Verify is an Internet-based system that compares a worker's authorization documents to Social Security and Homeland Security records to confirm the person's eligibility to work.

However, the Act grants a major exception to the one industry that arguably relies most heavily on undocumented labor: agriculture. In response to concerns by agricultural interests that a national roll-out of E-Verify would cripple the industry, the Legal Workforce Act grants them major concessions. While large businesses would have six months to begin complying with E-Verify requirements, agriculture would get a three-year pass before it would need to comply.   Furthermore, the act would only apply to new hires. This means that if a seasonal farmworker were to return to work on the same farm year after year, the person would be considered a returning worker and would never face a work eligibility check through E-Verify.

Farmworkers suffer some of the most serious human rights  abuses in the US, including child labor, unpaid wages, sexual violence, and serious health and safety violations. Human Rights Watch research has shown that undocumented status contributes significantly to the vulnerability of these workers. Fear of deportation and of losing their jobs keeps these workers in abusive work environments and prevents them from reporting these abuses.

Yet the Legal Workforce Act would not only allow farms to keep hiring undocumented workers without authorization, it would exacerbate the workers' susceptibility to abuse.

Under this Act, unauthorized workers already in the country would find themselves utterly dependent upon their employers for their livelihoods, since those who return to previous employers would never have their legal status checked through E-Verify. These workers would be vulnerable to all categories of abuse, from wage fraud or theft to sexual violence; and they would probably be even more fearful of exercising their rights because being fired would be tantamount to losing all opportunity to work in the US.

Were agriculture to obtain these loopholes, the national roll-out of E-Verify would no longer be a concern to the industry, but rather a boon. Case in point: earlier this year, when the Judiciary Committee discussed E-Verify in a hearing on agricultural worker visas, Rep. Dan Lungren, who represents an agricultural district in California, said that national E-Verify would create a "crisis in agriculture." Just a few months later, however, Lungren could be found as a listed co-sponsor on Smith's Legal Workforce Act.

Lamar Smith's Legal Workforce Act does one important service to the dialogue around immigration and work in the United States, though. It lays bare a truth: that American industries such as agriculture have depended on unauthorized workers, and that any increased immigration enforcement will need some kind of amnesty program alongside it. The Obama administration's immigration blueprint, released in May, says as much, stating that a national E-Verify system "must be accompanied by a legalization program that allows unauthorized workers to get right with the law."

For all the wrong reasons, the proposed Legal Workforce Act has advanced the immigration debate. The choice now facing Congress is either to support the Act's dirty amnesty, one that keeps immigrant workers undocumented, at risk and vulnerable, or champion a true amnesty that provides legal status to immigrant workers and pulls them out of the shadows. Respect for the human rights of workers demands the latter.

Antonio M. Ginatta is advocacy director for the U.S. program at Human Rights Watch.