A federal judge in Seattle on Thursday blocked Donald Trump's administration from enforcing an executive order limiting automatic birthright citizenship in the United States, calling it "blatantly unconstitutional."

At the urging of four Democratic-led states, U.S. District Judge John Coughenour issued a temporary restraining order blocking the government from enforcing the order, which the Republican president signed Monday on his first day in office.

The order has been the subject of five lawsuits filed by civil rights groups and Democratic attorneys general from 22 states, who say it flagrantly violates the U.S. Constitution.

"A baby born today is not a U.S. citizen under this order," Washington Assistant Attorney General Ryan Polozola told Senior U.S. District Judge John Coughenour at the start of a hearing in Seattle.

Polozola, who represents Democratic state attorneys general in Washington, Arizona, Illinois and Oregon, urged the judge to issue a temporary restraining order to block the administration from enacting this key element of Trump's immigration crackdown.

"This is a first step, but to hear the judge say that in his 40 years as a judge, he has never seen such a blatant violation of the constitution," Polozola said at a press conference outside the court after the restraining order was issued. The seriousness of the effort shocked him. "

Polozola and other challengers argued that Trump's actions violated his rights under the Citizenship Clause of the 14th Amendment, which stipulates that anyone born in the United States is a citizen.

In his executive order, Trump directed U.S. agencies to refuse to recognize the citizenship of children born in the United States if neither their mother nor their father is a U.S. citizen or lawful permanent resident.

In a brief filed late Wednesday, the Justice Department called the order "an integral part" of the president's efforts "to address this country's broken immigration system and the ongoing crisis at the southern border."

The lawsuit filed in Seattle is moving faster than four other cases filed under the executive order. The position has been assigned to Cougnour, who was appointed by Republican former President Ronald Reagan.

The judge could rule after hearing arguments, or he could wait to make a decision before Trump's order takes effect.

Under the order, any child born after February 19 whose mother or father is not a citizen or lawful permanent resident will be deported and will be unable to receive a Social Security number, various government benefits and benefits as they age. And the ability to get a job legally.

If Trump's order remains in effect, more than 150,000 newborns will be denied citizenship each year, according to Democratic-led states.

Democratic state attorneys general say the U.S. Supreme Court's ruling 127 years ago that children born in the United States to noncitizen parents is entitled to U.S. citizenship solidified understanding of the Constitution's citizenship clause.

The 14th Amendment was adopted in 1868 after the Civil War, overturning the Supreme Court's infamous 1857 Dred Scott decision, which declared that the Constitution's protections did not apply to enslaved black people.

But the Justice Department argued in its brief that the 14th Amendment had never been interpreted to universally extend citizenship to everyone born in the country, and that the Supreme Court's 1898 decision in United States v. Wong Kim Ark Only concerns children of permanent residents.

The Justice Department said the cases in those four states also "failed multiple thresholds." The department said only individuals, not states, can bring claims under the citizenship clause and that states lack the necessary legal standing to sue over Trump's order.

Trump's 36 Republican allies in the U.S. House of Representatives separately introduced legislation on Tuesday that would limit automatic citizenship to children born to citizens or legal permanent residents.