Updated

An appeal to lift a stay blocking Arizona's controversial law targeting illegal immigration was denied by a federal appeals court on Monday and said the federal government is likely to be able to prove it is unconstitutional.

The 9th U.S. Circuit Court of Appeals turned down an appeal filed by Gov. Jan Brewer. She had asked the appeals court to lift an injunction imposed by a federal judge in Phoenix the day before the controversial law was to take effect on July 29, 2010.

The U.S Justice Department sued to block the law, saying it violates the U.S. Constitution because enforcing immigration law is a federal issue.

U.S. District Court Judge Susan Bolton issued an injunction preventing four major parts of the law from going into effect pending a trial. Monday's ruling by the three-judge panel upheld that injunction.

The appeals court said the government is likely to succeed in its arguments that Congress has given the federal government sole authority to enforce immigration laws, and that the Arizona law violates the Supremacy Clause of the Constitution.

Brewer's lawyers said the federal government hasn't effectively enforced immigration law and that the state law will assist federal authorities.

Parts of the law blocked from taking effect while the case works its way through the courts include a provision requiring police to question people's immigration status while enforcing other laws if there is a reasonable suspicion they're in the country illegally. Other provisions placed on hold would require all immigrants to obtain or carry immigration registration papers; make it a state criminal offense for an undocumented immigrant to seek work or hold a job; and allow police to arrest suspected undocumented immigrants without a warrant.

In a separate opinion concurring with the panel's ruling, Appeals Court Judge Carlos Bea noted the intent of the state statute is clear and goes beyond what federal law allows.

"If we read Section 1 of the statute, the statute states the purpose of providing a solution to illegal immigration in the United States. So read, the statute is a singular entry into the foreign policy of the United States by a single state," he wrote.

The passage of S.B. 1070 last year reignited an immigration debate that has simmered in Arizona and across the nation for years.

Opponents of the law protested in the streets as it was about to take effect and called for a boycott of the state. Proponents called the law a long overdue effort by a state that has been overburdened by illegal immigration and a lack of federal action on the issue.

This report is based on the Associate Press. 

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