The internal and external security of Lesotho is the responsibility of the Defence Commission, which is established and defined by article 145 of the Lesotho national Constitution. The Prime Minister is the Chairman "ex officio", and there are six other Defence Commission members, namely the Commander and Deputy Commander of the Lesotho Defence Force, the Commissioner and Assistant Commissioner of the Lesotho Mounted Police Service, and the Director and Deputy Director of the Lesotho National Security Service. The Defence Commission has power to strategically direct the defence force, the police, and the prison service, but not the security service, which is answerable only to the Government. The Defence Commission has power to appoint or remove the senior staff of the defence force, police, and prison service, but not the security service, whose Director and Deputy Director are personal appointments of the Prime Minister.