Washington  - The last time the United States' three top automotive executives travelled from Detroit to Washington to plea for a federal bail-out, they flew each in their own corporate jets.

It was a public relations nightmare. One legislator noted the "delicious irony" of living the high life while asking for billions in emergency federal assistance.

Taking their case before Congress a second time on Thursday - seeking 34 billion dollars to help stave off bankruptcy - it appeared the group had learned its lesson.

"I'm proud to say that I drove a hybrid here from Detroit, and it performed - the technology performed extremely well," said Rob Nardelli, Chrysler chief executive.

Nardelli said that the more than 800-kilometre trip had to be split between two days. Not only did they use environmentally friendly cars this time - each executive proudly proclaimed that he didn't even hire a driver.

"I drove with a colleague. We split it up about 50-50. We drove down yesterday, and I'm going to drive back myself Friday or Saturday," General Motors Corp chief executive Rick Wagoner told the Senate Banking Committee.

"Where'd you stay? What did you eat?" quipped the committee's chairman, Senator Christopher Dodd.

Driving was not their only symbolic move. Ford Motor Co said it would sell its five corporate jets as part of an extensive recovery plan submitted earlier this week to Congress.

Wagoner assured the committee of the "cessation of all corporate aircraft operations."

Both Wagoner and Ford's Alan Mulally have pledged to take salaries of 1 dollar for 2009 in exchange for the federal funds. Chrysler's Nardelli said he's already working for 1 dollar a year.

While such moves will hardly return the auto industry to profitability on their own, the public relations campaign masks a broader argument that has been brewing during the US financial crisis.

Politicians and voters have regularly complained that Wall Street's ailing banks were being bailed out ahead of "Main Street," where ordinary Americans are struggling with a housing market collapse and shrinking spending power.

Dodd said that the auto industry's top labour union, the United Auto Workers, was the only group that has made concrete concessions.

UAW President Ron Gettelfinger on Wednesday said the powerful union would delay health-care payments, suspend pay for laid-off workers and modify their labour contracts with the Big Three carmakers. (dpa)