5A person holds and vacates office as the Commissioner or a Deputy Commissioner in accordance with the terms of the appointment, but—
(a)the initial term of office may not be more than 4 years,
(b)a person may be appointed for no more than 2 further terms of office (whether as the Commissioner or a Deputy Commissioner),
(c)a further term may not be more than 3 years,
(d)the person may resign by giving written notice to the Secretary of State, and
(e)the Secretary of State may dismiss the person if satisfied that the person is unable, unwilling or unfit to perform his or her functions.