These blocked provisions include:

-- The portion that requires officers to check a person's immigration status if there's reasonable suspicion they're in the country illegally;

-- The portion that creates a crime of failure to apply for or carry "alien-registration papers;"

-- The portion that makes it a crime for illegal immigrants to solicit, apply for or perform work;

-- The portion that allows for a warrantless arrest of a person where there is probable cause to believe they have committed a public offense that makes them removable from the United States.

"The court also finds that the United States is likely to suffer irreparable harm if the court does not preliminarily enjoin enforcement of these sections," Bolton states in the ruling. "The balance of equities tips in the United States' favor considering the public interest."

Other provisions of the law will still go into effect at 12:01 a.m. local time Thursday, such as the portion of the law that creates misdemeanors crimes for harboring and transporting illegal immigrants.

The ruling also says law enforcement still must enforce federal immigration laws to the fullest extent of the law when SB 1070 goes into effect at 12:01 a.m. Thursday. Individuals will still be able to sue an agency if they adopt a policy that restricts such enforcement.

Bolton's ruling followed hearings on three of seven federal lawsuits challenging SB 1070. The U.S. Department of Justice, the American Civil Liberties Union, Phoenix and Tucson police officers as well as municipalities, illegal immigrants and non-profit groups have all filed lawsuits challenging the draconian immigration law.

The ruling, seen as a last-minute victory for opponents of SB 1070, came as Arizona police from the U.S.-Mexico border to the Grand Canyon are getting last-minute training to enforce the law and protesters are planning large-scale demonstrations.

SB 1070, which was passed by Arizonan legislature and signed by Brewer in April, has created a heated national debate on how to deal with illegal immigration. The Justice Department has filed a lawsuit against Arizona over the law, calling the bill anti-Constitution.