A United States federal judge has temporarily blocked President Barack Obama's executive action to spare a range of undocumented immigrants from being deported.
US District Judge Andrew Hanen's decision on Monday gave a coalition of 26 states time to pursue a lawsuit that aims to permanently stop orders allowing as many as five million immigrants to stay in the US.
The federal government is expected to appeal the ruling to the 5th US Circuit Court of Appeals in New Orleans, but the Justice Department had no immediate comment late on Monday night.
Hanen's decision will not have any immediate effect because the first of Obama's orders - to expand a programme that protects young immigrants from deportation if they were brought to the US illegally as children - is not set to start taking effect until February 18.
The other major part of Obama's order, which extends deportation protections to parents of US citizens and permanent residents who have been in the country for some years, is not expected to begin until May 19.
In a 2013 ruling in a separate case, Hanen suggested the Homeland Security Department should be arresting parents living in the US illegally who induce their children to cross the border illegally.
The coalition of 26 states, led by Texas and made up of mostly conservative states in the South and Midwest, argues that Obama has violated the "Take Care Clause" of the US Constitution, which they say limits the scope of presidential power.
They also say the order will force increased investment in law enforcement, healthcare and education.
The White House has said Obama's executive order is not out of legal bounds and that the US Supreme Court and Congress have said federal officials can set priorities in enforcing immigration laws.
Past US Supreme Court decisions have granted immigration officials "broad discretion" on deportation matters.
Others supporting Obama's executive order include a group of 12 mostly liberal states, including Washington state and California, as well as Washington, D.C. They filed a motion with Hanen in support of Obama, arguing the directives will substantially benefit states and will further the public interest.