Per this:

The Senate voted Wednesday to require federal contractors to use an electronic employee eligibility verification system and to set construction standards for the fence now going up along the border with Mexico... [the first] was adopted by voice vote after a motion to kill it failed, 44-53. Sen. Jeff Sessions, R-Ala., offered the amendment, reflecting GOP frustration over the Obama administration’s delayed implementation of an executive order by President George W. Bush setting out the same requirement. The Obama administration has pushed back the Jan. 15 deadline for that order several times, most recently to September... Sessions’ amendment goes beyond the current rule to require federal contractors to check all employees using E-Verify, not just new hires...

The House might change it however.

The border-related amendment tries to prevent the Obama administration from cooking the books on what qualifies as a border fence;