http://www.privy-council.org.uk/output/page1.asp
The Privy Council Office currently forms a separate and independent part of the Constitution Directorate of the Ministry of Justice. The Office's Ministerial Head is the Lord President of the Council and Leader of the House of Lords, The Rt Hon Baroness Ashton of Upholland. The Clerk of the Council is Judith Simpson.
It has two principal functions:
To provide a Secretariat to the Privy Council and to support the Lord President
of the Council; and
To act as the Judicial Committee Office to the Judicial Committee of the Privy
Council.
The Privy Council Office is the Secretariat of the Privy Council. The Privy Council is the mechanism through which interdepartmental agreement is reached on those items of Government business which, for historical or other reasons, fall to Ministers as Privy Counsellors rather than as Departmental Ministers. This includes much business under the Royal Prerogative, including the affairs of Chartered bodies, as well as statutory areas where an Act of Parliament has given an order-making power to the Privy Council.