Conventional wisdom says that if the US economy takes a nosedive it would benefit the Democratic nominee in next year’s presidential election. As the Democratic frontrunner, Hillary Clinton is as aware as her rivals of the fact that US voters now cite the economy as their chief concern – ahead of the Iraq war and the threat of international terrorism.

Many believe that Mrs Clinton, who faces an increasingly intense battle for her party’s nomination but whom bookies still place as favourite to be the next US president, would shift to a more centrist economic platform were she to become her party’s nominee early next year.