LOS ANGELES - A national labor union launched a campaign yesterday against Countrywide Financial Corp., calling on union members and other consumers to boycott the mortgage lender's banking subsidiary until it guarantees it will not foreclose on borrowers who have fallen behind on adjustable-rate loans.

Unite Here, which represents more than 450,000 workers in the apparel manufacturing, hotel, restaurant and retail industries, asked consumers not to make deposits at Countrywide Bank and to send e-mails to the company demanding assurances that it will not foreclose on borrowers with mortgages that reset to higher rates last year and this year.

Countrywide, of Calabasas, Calif., and other lenders have been under intense pressure from lawmakers, consumer groups and others to do more to help stem a sharp increase in foreclosures.

Defaults and foreclosures have been most pronounced on adjustable-rate mortgages made to borrowers with credit problems. The subprime loans - for borrowers with poor credit records - typically require a lower monthly payment in the first two or three years before resetting to far higher amounts.

In October, Countrywide announced it would offer refinancing or modifications on $16 billion in loans with interest rates set to adjust by the end of 2008.

The company has also said it is trying to work out payment plans with thousands of other borrowers and has already helped more than 55,000 customers avoid foreclosure this year.

The union is concerned that Countrywide's loan-modification efforts will focus on borrowers who have yet to see their home loans reset, ignoring thousands of others who fell behind beginning last year, said Zakia Henderson-Brown, a research analyst for the union.

"It's a niche group of borrowers we're asking them to consider," Henderson-Brown said.

Countrywide officials did not return a phone call seeking comment.

By targeting Countrywide Bank, the labor union hopes to hurt the lender's ability to generate the funds needed to make new home loans.

Countrywide began relying on its banking arm to fund loans in the wake of the liquidity crisis that rattled financial markets after the spike in home-loan defaults this summer.

It has been aggressively courting new deposits and expanding its bank branches.