A federal judge responsible for deciding the merits of Georgia's new anti-immigration law has agreed to temporarily block enforcement of some of the law's most embattled parts.

U.S. District Court Judge Thomas Thrash issued the order Monday in Atlanta, mere days before House Bill 87 was set to take effect.

Civil rights groups had asked the judge to block its enforcement until a suit against the case could be settled.

Among other groups and individuals, the American Civil Liberties Union sued the state over the new law, claiming it violated Georgians' constitutional rights as well as the rights of residents from other states to travel through Georgia. They also claimed the bill preempted federal immigration laws.

The state's attorneys have argued the law seeks to preserve taxpayer dollars from being spent on illegal immigrants and have asked that the suit be dismissed in whole or in part.

Thrash's ruling Monday denied much of the state's request, but the judge did dismiss a claim that the law violated the Fourth and 14th amendments of the U.S. Constitution, as the state had requested.

Thrash also dismissed a claim that the bill violates the rights of residents from other states to travel in Georgia.

Two sections of the bill — one that makes it a crime to knowingly transport illegal immigrants and another that authorizes local law enforcement to check the immigration status of any suspect — are now on hold until the two sides can argue their merits.

Still, 21 of 23 sections of the law will go into effect as planned, Attorney General Sam Olens said in a news release.

Though Olens' statement expressed pleasure with the judge's decision to dismiss the claims that the bill violated the constitution, he did plan to appeal the judge's ruling that two sections of the bill preempted federal law.

Thrash blocked the two parts of the bill because he said the plaintiffs were likely to succeed in their claims that sections of House Bill 87 preempt federal law.

Also, he wrote, the law is likely to cause irreparable harm to the groups that have filed suit.

The law, by authorizing local law enforcement officers to verify a suspect's immigration status, gives local police "significant discretion" in how to enforce the bill, Thrash wrote.

The leeway "poses a serious risk that HB 87 will result in inconsistent civil immigration policies not only between federal and state governments, but among law enforcement jurisdictions within Georgia."

The risk is greater, Thrash writes, as other states such as Arizona and Wisconsin write and enforce their own immigration laws.

Also, Thrash challenged the bill's definition of "harboring" illegal immigrants.

The state's attorneys, in their defense of the bill, have said the state's definition mirrors federal definitions.

"The Defendants wildly exaggerate the scope of the federal crime of harboring under (federal law) when they claim that Plaintiffs are violating federal immigration law by giving rides to their friends and neighbors who are illegal aliens," Thrash wrote. "This is a good reason to require federal supervision of any attempts by Georgia to enforce federal immigration law."

Thrash called a claim by the state's attorneys that House Bill 87 sought to prevent exploitation of illegal immigrants "gross hypocrisy."

"The apparent legislative intent is to create such a climate of hostility, fear, mistrust and insecurity that all illegal aliens will leave Georgia," he wrote.

By allowing civil rights groups to continue arguing that Georgia is overstepping its boundaries in enforcing its own immigration statute, the judge's decision only reinforced the state's argument that the federal government is "an obstacle" when it comes to immigration problems, a spokesman for Gov. Nathan Deal said Monday.

"The state of Georgia narrowly tailored its immigration law to conform with existing federal law and court rulings," Deal spokesman Brian Robinson said in a statement. "Georgians can rest assured that this battle doesn't end here; we will appeal this decision."

But Thrash's decision Monday took also issue with the state's argument that "every day that passes with passive enforcement of the federal (immigration) law is a day that drains the state coffers."

Thrash wrote that immigration violations were prosecuted more than any other offense in federal court last year.

"The widespread belief that the federal government is doing nothing about immigration is the belief in a myth," Thrash wrote.

He said groups who have sued the state over the law's preemption of federal immigration law were likely to succeed.

"The varieties of immigration statuses are numerous and include many categories of individuals who have technically violated the immigration law but who are nonetheless present in the United States with the permission of the United States government, as well as many people who are awaiting adjudication of their removability or claims to asylum or other relief form removal," Thrash wrote.

He included paragraphs of federal immigration laws with little comment other than: "that remains the law of the land."

Similar laws elsewhere have met similar fates. A federal judge has blocked the most controversial parts of the law in Arizona, where Gov. Jan Brewer has said she plans to appeal to the U.S. Supreme Court.

In Utah, a federal judge temporarily blocked that state's law last month. A hearing is set for mid-July to determine if the law can go into effect.

And on Friday, a federal judge blocked parts of Indiana's law.

On Friday, many parts of the law will take effect. Among them is one that makes it a felony with hefty penalties to use false information or documentation when applying for a job. Another creates an immigration review board to investigate complaints about government officials not complying with state laws related to illegal immigration.

Starting Jan. 1, businesses with 500 or more employees will have to use a federal database to check the immigration status of new hires, a requirement that will be phased in for all businesses with more than 10 employees by July 2013.

Also starting Jan. 1, applicants for public benefits will have to provide at least one state or federally issued "secure and verifiable" document.

Associated Press contributed to this report.