Expressing frustration with the lack of a federal immigration law overhaul, Gov. Janet Napolitano of Arizona signed a bill yesterday providing what are thought to be the toughest state sanctions in the country against employers who knowingly hire illegal immigrants.

Ms. Napolitano, a Democrat, called the bill flawed and suggested that the Arizona Legislature reconvene to repair problems with it, but she nevertheless moved forward “because Congress has failed miserably,” she wrote in a statement.

The bill requires employers to verify the legal status of their employees. If they fail to do so, they risk having their business licenses suspended. A second offense could result in the “business death penalty,” a permanent revocation of the state business license, effectively preventing a business from operating in the state.

Ms. Napolitano said she was concerned, among other problems, that under the law hospitals and nursing homes could end up shuttered because of hiring one illegal immigrant. She also said the bill did not provide enough money for the state attorney general to investigate complaints.

Although federal law already makes it a crime to hire illegal workers, supporters of the Arizona bill have said enforcement is lax.

Ms. Napolitano sent a letter to Senator Harry Reid, Democrat of Arizona and the majority leader, and Speaker Nancy Pelosi, Democrat of California, saying Congressional inaction on immigration was forcing states to act.

Ms. Napolitano’s decision had been anxiously awaited in Arizona, the state where more people cross illegally into the United States than any other.

Last year, Ms. Napolitano vetoed an employer-sanctions bill, saying that its language was flawed and that it would not achieve its goals.

(Published by The New York Times, July 3, 2007)