DETROIT—Worried about their jobs and warned that the cost of failure could be a depression, hundreds of leaders of the United Auto Workers voted overwhelmingly Wednesday to make concessions to the struggling Detroit Three, including all but ending a much-derided program that let laid-off workers collect up to 95 percent of their salaries.

“Everybody has to give a little bit,” said Rich Bennett, an official for Local 122 in Twinsburg, Ohio, representing Chrysler workers. “We’ve made concessions. We really feel we’re doing our part.”

Union leaders also agreed to let the cash-starved automakers delay billions of dollars in payments to a union-administered trust set to take over health care for blue-collar retirees starting in 2010.

In addition, they decided to let the Detroit leadership begin renegotiating elements of landmark contracts signed with the automakers last year, a move that could lead to wage concessions. The vote came on the eve of congressional hearings on as much as $34 billion in loans that General Motors and Chrysler say are critical to their survival. Ford has said it may be able to hang on through 2009 without additional credit.

UAW President Ron Gettelfinger said the union must help persuade Congress to offer the loans or risk destroying what he said is the country’s economic spine.

Earlier in the day, Chrysler Vice Chairman Jim Press went a step further, warning of a depression if even one automaker runs out of cash.

“We’re on the brink with the U.S. auto manufacturing industry,” Press told The Associated Press in an interview. “If we have a catastrophic failure of one of these car companies, in this tender environment for the economy, it’s a huge blow. It could trigger a depression.” Both Chrysler LLC and General Motors Corp. are so perilously low on cash that the companies may not be able to pay all their bills by the end of the year. GM wants a total of $18 billion in loans. Chrysler is seeking $7 billion, and both manufacturers say they need cash this month.