5 Million affected as FEDERAL JUDGE HALTS OBAMA'S IMMIGRATION ACTION : While the injunction does not pronounce Obama's actions illegal, it prevents the administration from implementing them until the court rules on their constitutionality. The federal government is expected to appeal the ruling.

WASHINGTON -- A federal judge issued a preliminary injunction on Monday that will temporarily prevent the Obama administration from moving forward with its executive actions on immigration while a lawsuit against the president works its way through the courts.

Obama

The order, by Judge Andrew Hanen of the U.S. District Court in Brownsville, Texas, was an early stumble for the administration in what will likely be a long legal battle over whether President Barack Obama overstepped his constitutional authority with the wide-reaching executive actions on immigration he announced last November.

While the injunction does not pronounce Obama's actions illegal, it prevents the administration from implementing them until the court rules on their constitutionality. The federal government is expected to appeal the ruling.

The impact of the order will be felt almost immediately: One of Obama's actions is set to take effect on Feb. 18. On that day, the administration was set to begin accepting applications for an expanded version of the Deferred Action for Childhood Arrivals, or DACA, program. DACA allows undocumented immigrants who came to the U.S. as children to stay in the country and work legally. more