BIRMINGHAM, Ala (Reuters) - Civil rights groups on Friday filed a lawsuit challenging Alabama's new immigration law, described as the toughest in the nation by both critics and supporters.

The lawsuit says Alabama's law will subject both citizens and non-citizens to "criminal penalties and incarceration for innocent daily activities, such as giving a ride to a neighbor, hiring a day laborer, or renting a room to a friend."

The suit also says the law will deter children in immigrant families from enrolling in public schools. Alabama's law is unique in requiring public schools to determine, by review of birth certificates or sworn affidavits, the legal residency status of students upon enrollment.

Republican Governor Robert Bentley signed the crackdown into law in June, and it is set to take effect September 1.

Alabama joins Georgia, Arizona, Utah and Indiana in defending new immigration laws in federal court. Judges have blocked key parts of laws passed in those states.

"Alabama has brazenly enacted this law despite the clear writing on the wall: Federal courts have stopped each and every one of these discriminatory laws from going into effect," said Cecillia Wang, director of the American Civil Liberties Union's Immigrants' Rights Project.

The coalition filing the class action lawsuit includes the ACLU, Southern Poverty Law Center, ACLU of Alabama, National Immigration Law Center, Asian Law Caucus and Asian American Justice Center.

The legal challenge did not come as a surprise, and one of the law's sponsors said on Friday he is confident the Alabama law will hold up in court.

"It is important to note that our law seeks to protect immigrants who reside here legally while affecting only those who break our laws with their simple presence," said House Majority Leader Micky Hammon, a Republican from Decatur.

"We cannot turn a blind eye toward those who thumb their noses at our borders and our laws," he said in a statement.

Under the Alabama law, police must detain someone they suspect of being in the country illegally if the person cannot produce proper documentation when stopped for any reason.

It also would be a crime to knowingly transport or harbor someone who is in the country illegally. The law imposes penalties on businesses that knowingly employ someone without legal resident status. A company's business license could be suspended or revoked.

The law requires businesses to use a database called E-Verify to confirm the immigration status of new employees.

(Editing by Colleen Jenkins and Greg McCune)

Source: Reuters US Online Report Domestic News