States are threatening to challenge in court and even disobey new orders from Congress to start issuing more uniform driver's licenses and verify the citizenship or legal status of people getting them.

There is concern among some states that they'll get stuck with a large tab to pay for implementing the new rules and that getting a driver's license will become a bigger headache for law-abiding residents.

"Governors are looking at all their options. If more than half of the governors agree we're not going down without a fight on this, Congress will have to consider changing this unfunded federal mandate," said Arkansas Gov. Mike Huckabee, vice chairman of the National Governors Association (search). A Huckabee aide said the options include court action.

States fear the new rules may force applicants to make more than one trip to motor vehicle departments, once to provide documents such as birth certificates that states must verify and a second time to pick up the license, state officials said.

"What passed is something that will be an enormous amount of work and it's questionable what it's going to yield," said Democrat Matt Dunlap (search), Maine's secretary of state. "Is it going to yield national security or is it going to be hassle for people already complying with the law?"

The immigration requirements were attached to an $82 billion spending package for military operations and construction in Iraq (search) and Afghanistan (search) that the House passed last week. The Senate is expected to vote this week and send the bill to President Bush.

"We'd like to work with people to implement the needed reform and will be very disappointed if these groups thwart these important rules," said Jeff Lungren, spokesman for Wisconsin Republican Rep. James Sensenbrenner (search), who wrote the new requirements.

Sensenbrenner said last week that waiting a little longer in line is "a small price to pay" to prevent future terrorism.

All but one of the 19 hijackers in the Sept. 11, 2001, attacks had some form of U.S. identification, some of it fraudulent, the Sept. 11 commission (search) found. The commission recommended the federal government set standards for birth certificates and other identification documents, including driver's licenses.

Some states already have been increasing their license requirements, but their work may not be enough.

Maine's motor vehicle department is upgrading its computer system. But the upgrade doesn't include computer coding to comply with at least one of the new rules: ensure driver's licenses issued to temporary legal residents expire when the resident's authorized time in the U.S. is up.

"That adds to the cost and throws everything into the woods," Dunlap said.

Virginia's motor vehicle department estimated it would have to spend $237 million to comply with the bill passed by the House if it maintains its current level of customer service. Some changes to the final legislation could alter the estimate, a spokeswoman said.

The bill allows the Homeland Security secretary to offer grants to help states to comply, but doesn't provide money.

States will have three years after the president signs the bill to obey the rules. If they don't, their residents won't be able to board planes or enter federally protected buildings.

States also question how they will verify birth certificates, whose appearance vary widely by state and county. Dunlap said his state has only a portion of birth certificates online.

Thirty-six states and the District of Columbia verify Social Security numbers online with the federal government or by another method, said Mark Lassiter, Social Security Administration spokesman.

In fiscal 2004, which ended Sept. 30, Social Security handled 18 million verification requests, rejecting 2 million numbers, Lassiter said. But the system isn't foolproof.

California found many numbers were rejected for women who failed to change their name with when they married, said Bill Branch, motor vehicle department spokesman.

Another concern for states is preventing identity theft if licenses carry more information, said Michael Balboni, a Republican New York state senator. Balboni and Dunlap represented the National Conference of State Legislatures on a now defunct panel Congress created in December to design new driver's license rules. The conference opposes the new rules.

"What's so ironic about this bill is everybody agrees with the concept, one person, one driver's license," Balboni said. "How you get there is really the tough issue."