Constitutional Reform and Governance Bill

My hon. Friend has just referred to the chairman of the National Audit Office having some involvement in the selection of the current Comptroller and Auditor General. Will he elaborate a little further on the relationships involved, in the context of the appointment of a Comptroller and Auditor General? The Prime Minister is involved, as is the Chairman of the Public Accounts Committee, but what is the role of the chair of the National Audit Office in the appointment of its chief executive?