Washington: Presumptive Republican presidential nominee Donald Trump has overtaken his Democratic rival, Hillary Clinton, in the key states of Florida and Pennsylvania, according to a voter survey published on Wednesday by Quinnipiac University. Trump is leading Clinton by 42 per cent to 39 per cent in Florida, although last month the former secretary of state had been eight percentage points out in front of the real estate magnate, EFE news agency reported. Meanwhile, in Pennsylvania, another state that could just as easily go for the Democratic or the Republican in the November election, Trump is leading Clinton by 43 per cent to 41 per cent, although last month the billionaire was trailing the former first lady by one percentage point. The two candidates were tied at 41 per cent in Ohio, yet another swing state and one that the winner of the presidential election has virtually always won. Given the error margin of about 3 per cent for these surveys, the newly published results indicate that the races are too close to call. Clinton's drop in the polls comes after FBI Director James Comey last week criticised the "extremely careless" way in which she and her staffers handled e-mail communications when they were working at the State Department, in particular using a private server through which classified information was sent and received. However, Comey said he saw no reason to recommend that Clinton be indicted for her handling of e-mails while she was the top US diplomat, something that has sparked criticism that he gave favourable treatment to someone considered to be a member of Washington's political elite. If the Quinnipiac poll includes candidates from minor parties - such as the Libertarian Party and the Green Party - Trump leads Clinton in all three states, particularly in Florida by 41-36 per cent and in Pennsylvania by 40-34 per cent. The survey was conducted between June 30 and July 11 among about 1,000 registered voters in each of the three states and has an error margin of a little over 3 per cent. These three states are the focus of the survey because since 1960 no candidate for president has won the White House without winning at least two of them.