A federal judge has temporarily blocked President Donald Trump’s executive order ending the constitutional guarantee of birthright citizenship regardless of the parents’ immigration status.

A federal judge temporarily blocked President Trump’s executive order that aims to restrict automatic citizenship to babies born on U.S. soil, calling it “blatantly unconstitutional.” The order Mr. Trump signed on Monday was an effort to upend the nation’s immigration laws and reverse decades of precedent and would affect children born to undocumented or temporary immigrants.

A federal judge Thursday blocked President Donald Trump’s executive order outlawing birthright citizenship—the policy automatically giving citizenship to anyone born in the U.S.—and declared it “blatantly unconstitutional,