Criticizing a lack of congressional action on immigration reform, two key members of the Bush administration rolled out a new plan Friday to crack down on workers whose names don't match their Social Security numbers and the employers who hire them.

Homeland Security Secretary Michael Chertoff and Commerce Secretary Carlos Gutierrez said Friday the action was needed in the absence of new laws.

"We're obviously disappointed in the fact, as is the president, that Congress has not chosen to act on our comprehensive solution," Chertoff said, referring to a failed Senate bill that would have provided a pathway to legal status for most of the nation's 12 million undocumented residents and bolster enforcement. "But until Congress chooses to act, we're going to be taking some energetic steps of our own."

The new regulations, which take effect in 30 days, give employers 90 days to either clear up mismatches between names and Social Security numbers when they receive a letter from the Social Security Administration, or fire the employee. They also boost by "about 25 percent" civil fines for employers who don't comply with the law. Enhancements to a federal Internet-based verification program, now called E Verify were also announced.

Farmers and other employers who rely on immigrant labor said the stepped-up enforcement could drive them out of business. And immigrant rights activists said the regulations could drive an underground economy further underground.

"Everyone's very anxious," said Paul Schlegel, director of public policy for the American Farm Bureau Federation in an Associated Press interview. "We're heading into the busiest time of the year for agriculture, so you're going to see a lot of worry from farmers and employers about how you deal with this."

In Utah, Tony Yapias, director of Proyecto Latino de Utah, predicted that "it's going to cause massive layoffs in every sector of our economy. We're going to start seeing the impact."

Saying that as many as 4 percent of the 250 million wage reports filed with the Social Security Administration each year are mismatches, officials described the regulations as "guidelines." Gutierrez added the administration was also working to make the existing worker visa program more workable, especially when it comes to agricultural workers.

Gutierrez said employers have told the government "consistently" that they do not have the tools to enforce the law.

"What we're going to do with our executive branch authority, the president's authority, is to give employers tools to the extent that we can. But this is all about giving them tools that they repeatedly have told us they did not have."