New York votes for its mayor in a week’s time and the contest is turning mean. Michael Bloomberg, the incumbent and the city’s richest man, is squaring off against Bill Thompson, the Democratic underdog, over who is better equipped to guide the US financial capital out of recession with a minimum of pain.

With the challenger struggling to overtake the mayor’s double-digit opinion poll lead, some of his supporters now want to turn the November 3 poll into a referendum on Wall Street by targeting Mr Bloomberg as a candidate of the rich who is aloof from the economic worries of most New Yorkers.