Hopes of quickly securing $25bn in emergency government support for troubled US carmakers have been caught in a stand-off between the outgoing Bush administration and, on the other side, congressional Democrats and Barack Obama, the president-elect.

As bad news about the health of the big three carmakers in Detroit multiplied during the past 10 days, the White House came under pressure to justify its decision to rescue swathes of the financial services industry while ignoring the motor manufacturers.