A federal judge on Thursday temporarily blocked President Donald Trump’s executive order denying U.S. citizenship to the children of parents living in the country illegally.

In the ruling, the judge called it “blatantly unconstitutional."

The case stems from the 14th Amendment, which grants citizenship to those born in the U.S..

Trump’s order drew immediate legal challenges across the country, with at least five lawsuits being brought by 22 states and several immigrant rights groups.

The decision prevents the Trump administration from taking steps to implement the executive order for 14 days but also sets up a massive legal battle that is likely heading for the U.S. Supreme Court in a hurry.

"It's a total revamping of our federal government in ways that we've never seen before," Pace University law professor Ben Gershman said.