Michel Barnier and Olli Rehn have written to George Osborne in response to his letter which had asked them not to diverge from Basel III and to allow Member States flexibility in implementation so they could impose higher standards if they wished. The letter thanks George Osborne for his support but says the EU will need to adapt Basel III to its specific circumstances and to accommodate investment firms as well as banks. It also says maximum harmonisation is an important feature of the single rule book, although it could allow some flexibility for country-specific issues. (Source: Wall Street Journal Letter from Michel Barnier)