President George W. Bush signed into law a package of measures intended to tackle the US housing crisis in a low-key early morning ceremony on Wednesday, surrounded by several top administration officials but no congressional leaders.

The bill includes new powers for the US Treasury to pump money into Fannie Mae and Freddie Mac and a tougher regulator for the two government-sponsored mortgage companies, which have suffered big losses during the slump but have accounted for a growing proportion of the mortgage market.