The federal government’s crackdown on illegal immigration could cause massive layoffs, which in turn could create severe labor shortages in some industries and weaken the overall economy, some business lobbyists say.

According to the Austin Business Journal, the Department of Homeland Security will begin mailing letters this week that outline steps an employer must take if the Social Security Administration notifies them that an employee’s name and Social Security number don’t match government records. About 15,000 letters will be mailed to companies each week for the next two months.

Employers who receive a letter from the SSA should make sure there was not a clerical error in the information and then check the accuracy of the information with the employee. If necessary, the employer must ask the employee to contact the SSA to resolve the discrepancy, and if the problem is not resolved in 90 days, he or she must terminate the employee or risk being held liable for violating immigration laws. Such letters were often ignored in the past, but a new regulation means these letters can be used as evidence that employers knowingly hired illegal immigrants.

The DHS is also considering increasing civil fines against employers who violate immigration laws and will seek criminal charges against the worst offenders. It has already arrested 742 people for workplace violations this year, up from just 24 in 1999.

Business lobbyists predict the tougher standards will cause many employees to quit and employers to discriminate against Hispanic workers. In addition, illegal immigrants could move to the underground economy instead of returning to their home countries, said Angelo Amador, director of immigration policy for the U.S. Chamber of Commerce, which could cost the U.S. government billions of dollars in taxes. He added that businesses may have to hire attorneys, human resources specialists and other consultants to comply with new regulations, which could cause them to increase the amount of work they outsource to other countries.