Behind the glass- and marble-clad great arch of La Défense - built at the behest of François Mitterrand two decades ago - another French president is preparing an even more ambitious grand projet for Paris.

Nicolas Sarkozy is planning a massive expansion of the business district on the north-western edge of Paris to challenge the City of London as Europe's pre-eminent financial centre. In spite of his tirades against financial capitalism, Mr Sarkozy wants a bigger slice of the business.