The US House of Representatives has approved bailout plans for General Motors and Chrysler that include tough conditions on restructuring in return for taxpayer help.

The legislation, however, still faces an extremely bumpy ride in the Senate, where approval is far from assured.

"It's going to be tough, but we haven't lost all hope," one Democratic aide said of the plan's chances in the Senate.

The vote could take place today as the Detroit companies say they need at least $14 billion (£9.45 billion) to survive only to early next year.

"This legislation is about offering Detroit and America a chance to get back on track," House Speaker Nancy Pelosi said in a floor speech before the vote. She stressed that the companies faced stiff conditions in return for the money. "It gets down to a question of tough love." The House passed the measure by 237 to 170.

Senator Richard Shelby, an Alabama Republican and ranking member of the Banking Committee, has been vocal in his opposition to the measure.

"Unless Chrysler, Ford and General Motors become lean and innovative and competitive in the market place, this is only delaying their funeral," he said.

Approval of the rescue package for GM, headed by Rick Wagoner, could prove vital to its British unit Vauxhall that has already indicated it may need government help.

British-based carmakers are feeling the crunch as well, with Jaguar Land Rover, bought earlier this year by the Indian conglomerate Tata, saying it wants a £1 billion bailout.

Business Secretary Peter Mandelsonindicated the government may be reluctant to assist. "We will not be supporting companies with flawed business plans and companies with no prospect of recovery," he said recently.

However Mandelson said he may make an exception where the collapse would have a dramatic effect on unemployment or business confidence.

The Bush White House now supports the Detroit rescue package after demanding that a so-called "car czar" be appointed to assess whether the companies were doing enough to restructure for future profitability. The "car czar" could recommend bankruptcy if the official restructuring plans are deemed inadequate.

The Bush Administration weighed in before the House vote with an endorsement aimed at convincing sceptical Republicans.

"We believe the legislation developed in recent days is an effective and responsible approach to deal with troubled automakers and ensure the necessary restructuring occurs," a White House spokeswoman said.