On December 28, 2007, President Bush vetoed legislation which would have amended the Family and Medical Leave Act of 1993 to allow employees to use leave in certain circumstances when their spouse, child, or parent is called for active duty in the military.
The FMLA provision was part of a larger defense bill (H.R.1585, the National Defense Authorization Act). According to a White House fact sheet, President Bush vetoed the legislation "because particular provisions included in the bill risk imposing financially devastating hardship on Iraq that will unacceptably interfere with the political and economic progress everyone agrees is critically important to bringing our troops home."
The move came as a big surprise to leaders in Congress who fully expected Bush to approve the legislation. Since the veto had nothing to do with the provision that would have amended the FMLA, it's possible that Congress could again pass legislation including a similar provision.