The US economy would become "dramatically worse", wrecking the dreams of a generation of Americans, if Congress did not act quickly to drive through huge fiscal stimulus plans, Barack Obama said yesterday as fresh data indicated that the recession was deepening.

In his most high-profile speech since the election, the president-elect ratcheted up the rhetoric to press lawmakers who are threatening delays to his stimulus package. He said the unemployment rate was in danger of reaching double digits and the recession "could linger for years" without urgent intervention.