This executive order amends executive order 12989 and directs all "federal departments and agencies to require contractors, as a condition of each future federal contract, to agree to use an electronic employment eligibility verification system - designated by the Secretary of Homeland Security - to verify the employment eligibility of all persons hired during the contract term and all persons performing work within the United States on the federal contract." In response to this Executive Order, Secretary Michael Chertoff designated E-Verify as the system of choice to ensure that the federal government only does business with companies that agree to verify the legality of their new hires and further, that the specific employees tapped to perform contract services in the United States for the federal government are authorized to work in this country.
Executive Order 13465; EO 13465
Federal Register: http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR
Federal Register (June 11, 2008), v.73 no.113, p.33285-33287