Immigration and human rights experts say that no other developed country has passed an immigration law as stringent as Alabama’s.

Although pieces of the law have been blocked by federal courts, some sections have gone into effect, including a provision that bans courts from enforcing contracts made with unauthorized immigrants. While some states have banned public agencies from making contracts with unauthorized immigrants, no state or developed country has prohibited courts from enforcing any contract with the undocumented, say experts in immigration and human rights.

“We don’t know of a similar parallel, either internationally or elsewhere in the United States, where contracts with unauthorized immigrants are deemed unenforceable,” says Michelle Mittelstadt, communications director for the Migration Policy Institute.

“The bottom line is that Alabama’s law is a complete outlier,” says Alison Parker, director of Human Rights Watch’s U.S. program. “The only country where we are aware of something that comes close to what Alabama has done” is Italy, she said, pointing to a law that makes it illegal to rent to to unauthorized immigrants. “What they are doing in the state of Alabama runs in the face of human rights law.”

European countries have traditionally been viewed as less welcoming of immigrants than the United States, which for much of its history allowed migrant workers to cross the borders with Mexico and Canada without clearance from a government agency. Parker’s colleague Benjamin Ward, deputy director of Human Rights Watch’s European program, called Alabama’s law “unbelievable and horrific.”

Throughout the twentieth century, border security efforts have steadily increased, and repeated attempts have been made to bring formerly unlimited quantities of new immigrants down to what’s considered by policymakers to be a manageable level.

But Parker says there’s an important distinction between controlling immigration at the border and stripping rights from immigrants already in the country.

“Everyone has the right to a family life, to a roof over one’s head, to compensation for work,” says Parker. “Once people are here, there are certain fundamental rights protected by human rights law.” European governments have tended to adhere to that standard.

Mittelstadt points out that immigrants in Europe tend to be registered with the government, which means that the contract rights of immigrants aren’t likely to be subject to Alabama-style laws: “In Europe, where national ID cards and registration programs for foreigners prevail, employers and others would not be likely to enter into contracts with unauthorized immigrants.”

At this point it’s unclear how the Alabama immigration law will be interpreted by the federal courts, including the U.S. Supreme Court, which is likely to step in now that the appellate courts have issued different decisions on state-level “enforcement only” laws (the Ninth Circuit upheld a decision to block Arizona’s immigration law from going into effect earlier this year).

The ban on contracts is especially murky, and there are few precedents that experts can point towards to predict its viability in the courts. The most relevant precedent could be a 2002 Supreme Court case, Hoffman Plastic v. NLRB, in which the court ruled that unauthorized immigrants aren’t entitled to back pay under the National Labor Relations Act. But the Court did establish that unauthorized immigrants were “employees” under the Act and had the right to organize.

However, it may be Alabama’s own state constitution that determines the fate of the contract ban.

As ThinkProgress reported, an Alabama state judge indicated in a decision earlier this week that the contract ban appears to violate Section 95 of Alabama’s own constitution, which states:

There can be no law of this state impairing the obligation of contracts by destroying or impairing the remedy for their enforcement; and the legislature shall have no power to revive any right or remedy which may have become barred by lapse of time, or by any statute of this state. After suit has been commenced on any cause of action, the legislature shall have no power to take away such cause of action, or destroy any existing defense to such suit.

In an opinion on a breach of contract lawsuit filed by an undocumented immigrant, Alabama Circuit Judge Scott Vowell wrote, “It may well be that that [the Alabama immigration law] also violates this section of the constitution” by “impairing the obligation of contracts.”

But since the case in question was filed before the immigration law went into effect, the judge didn’t outright rule the section unconstitutional, merely that the law could not take away an immigrant’s “cause of action” or “existing defense” after his or her case has already been filed.