Homeland Security Secretary Michael Chertoff said that President George Bush has signed a directive putting the requirements in place, thus bringing federal contractors under the same requirements already in effect for federal agencies, the Washington Times reported Tuesday.

The contractors must now use the E-Verify system to check employees' legal resident status. The system is operated by the Social Security Administration and Citizenship and Immigration Services, and the government claims 70,000 employers have already enrolled in the program, the Times reported.

But some business groups and state legislators say it's unreliable. For instance, the Illinois General Assembly last year prohibited employers from enrolling in E-Verify, but agreed to suspend the measure if E-Verify could be made to reduce the number of false-positive results, the newspaper said.

Civil libertarians also have raise objections to the program.