A private secretary (PS) is a civil servant in a governmental department or ministry, responsible to a secretary of state or minister.
A private secretary is normally of middle management level; however, as the key official responsible for disseminating the decision of ministers and indeed as their gatekeeper, his or her role is of considerably greater significance than this grade or level suggests. Depending on what level of politician the official works for they will be assisted by one or more assistants and or deputy secretaries, or even head a whole office in which those may be section chiefs.
A junior minister may have a two-person private office consisting of a private secretary and an assistant private secretary. Whereas a cabinet secretary may have a five-person private office consisting of a private secretary, two deputy private secretaries and two assistant private secretaries. The same applies to the prime minister’s private office but on a much larger scale.
Where the private secretary is a member of the Senior Civil Service, he or she will be referred to as a principal private secretary, making the order of precedence principal private secretary, senior private secretary (rarely now in existence), private secretary and assistant private secretary (APS). A similar role to a principal private secretary in the United States administration would be a chief of staff.
The private secretary is the principal link between a government minister and officials in the Department or Ministry. He or she has overall responsibility for coordinating the development of the minister's policy remit, ensuring that the aims of ministers are clearly and fully implemented by the department. In that respect a PS and APS will often be in a position of debate with colleagues of much higher seniority.
A PS or an APS is always in attendance with the minister at every meeting or event to provide support and to ensure that a member of the UK civil service, who are non-political appointees, takes a factual note of discussions and commitments.
They also have ownership of the ministerial diary, managing the ministerial diary secretary whose task is to sift and prioritise invitation, commitments, policy briefings and parliamentary business. A PS is always the initial source of advice to Ministers on parliamentary protocol, the process of cabinet business and departmental policy.