"Where is the truth when you pretend to be Thatcher in London and Mitterrand in Paris?" he said at a campaign rally of 7,000 supporters in the southern city of Marseille on Sunday.
The president was referring to an interview François Hollande gave to British journalists a week ago.
The Guardian newspaper reported that Hollande said the City of London should not be afraid of his drive for more regulation in the financial world.
He told the journalists he was not "aggressive" or seen in France as very leftwing.
Earlier in January, Hollande told a campaign rally in France his "adversary" was "the world of finance."
At the rally Sarkozy sought to position himself as the only candidate who can save steer the country through difficult economic times, claiming he had saved France from "catastrophe" during the recent eurozone crisis.
Latest polls continue to suggest that a second-round run-off between the two frontrunners would see Hollande win by 55 percent to Sarkozy's 45 percent.