A federal judge in Texas has refused to lift a temporary block on a White House immigration plan that would shield millions of undocumented immigrants from deportation, court documents show.

U.S. District Judge Andrew Hanen in Brownsville, a city along the border with Mexico, rejected a U.S. Justice Department request to remove his Feb. 16 stay on President Barack Obama's immigration actions.

Twenty-six U.S. states filed a lawsuit contending that Obama exceeded his powers with executive actions that would let up to 4.7 million undocumented immigrants stay in the country without threat of deportation. Obama's actions bypassed Congress, which has not been able to agree on immigration reform.

Immigration policy promises to become a major issue in the 2016 general election. Silicon Valley donors have shown a willingness to spend money and political capital on easing restrictions on work visas, hoping to make it easier to hire from abroad. These measures face stiff opposition from the Republican Party's base.

Texas Attorney General Ken Paxton said in a statement on Tuesday that the Obama administration misled the court regarding early implementation of expanded work permits to undocumented immigrants. At issue is a U.S. government filing that said some 100,000 people were given three years of deferred action before Hanen's injunction.

"Any premature implementation could have serious consequences, inflicting irreparable harm on our state, and this ruling is key in determining the extent to which the federal government did not present the full truth in this case," Paxton said.

The Justice Department, which could not be immediately reached for comment, requested on Feb. 23 an emergency stay of Hanen's decision. It has also filed a notice of appeal to the 5th U.S. Circuit Court of Appeals in New Orleans, court documents show.

That court on Tuesday rejected a challenge to Obama's 2012 executive action granting deportation relief to immigrants brought to the U.S. illegally as children, upholding a lower court's ruling.

The issue of immigration reform and immigrant rights became even more pressing last summer as thousands people, including many children unaccompanied by adults, made their way from crime- and drug-plagued parts of Central America. Some are still waiting for their cases to be processed.

The White House did not issue an immediate comment.

Reuters