The lawyers are moving in. This is going to get expensive.....

WHEN BORROWERS FIGHT BACK: Banks watch closely to see if a couple's legal struggle with their lender will launch a new front in the battle over troubled mortgages.

A federal appeals court is nearing a decision on a battle between Chevy Chase Bank and a Wisconsin couple that could for the first time enable homeowners across the country to band together in class-action lawsuits against mortgage firms and get their loans canceled.

The case is alarming Wall Street's biggest banks, which could bear the hefty cost of reimbursing all mortgage interest, closing costs and broker fees to groups of homeowners who uncover even minor mistakes in their loan documents.

After a federal judge in Milwaukee ruled last year that the Wisconsin couple had been deceived and other borrowers could join their suit, Chevy Chase Bank appealed to the circuit court in Chicago. Kevin Demet, the lawyer for the plaintiffs, said a decision by the appeals court is imminent, though others involved in the case said it could be a matter of weeks.

"It's one of the most important cases for the mortgage industry right now," said Louis Pizante, chief executive of Mavent, which provides consumer protection law services to major lenders. "The case was somewhat interesting a couple years ago when it started, but its ramifications and impact have completely changed given the current environment."