see - sc.judiciary.gov.ph/jurisprudence/2013/april2013/194994.pdf
"x x x.
Amores v. Civil Service Commission38 is instructive as to the nature of
temporary appointments in the CES. The Court held therein that an
appointee cannot hold a position in a permanent capacity without the
required CES eligibility:
We begin with the precept, firmly established by law and jurisprudence that a permanent appointment in the civil service is issued to a person who has met the requirements of the position to which the appointment is made in accordance with law and the rules issued pursuant thereto. An appointment is permanent where the appointee meets all the requirements for the position to which he is being appointed, including the appropriate eligibility prescribed, and it is temporary where the appointee meets all the requirements for the position except only the appropriate civil service eligibility.
x x x x
With particular reference to positions in the career executive service (CES), the requisite civil service eligibility is acquired upon passing the CES examinations administered by the CES Board and the subsequent conferment of such eligibility upon passing the examinations.
Once a person acquires eligibility, he either earns the status of a permanent appointee to the CES position to which he has previously been
appointed, or he becomes qualified for a permanent appointment to that
position provided only that he also possesses all the other qualifications
for the position. Verily, it is clear that the possession of the required CES
eligibility is that which will make an appointment in the career executive
service a permanent one. Petitioner does not possess such eligibility,
however, it cannot be said that his appointment to the position was
permanent.
Indeed, the law permits, on many occasions, the appointment of
non-CES eligibles to CES positions in the government in the absence of
appropriate eligibles and when there is necessity in the interest of public
service to fill vacancies in the government. But in all such cases, the
appointment is at best merely temporary as it is said to be conditioned on
the subsequent obtention of the required CES eligibility. This rule,
according to De Leon v. Court of Appeals, Dimayuga v. Benedicto,
Caringal v. Philippine Charity Sweepstakes Office, and Achacoso v.
Macaraig, is invariable even though the given appointment may have been
designated as permanent by the appointing authority.
x x x x
Security of tenure in the career executive service, which presupposes a permanent appointment, takes place upon passing the CES examinations administered by the CES Board x x x.
Petitioner undisputedly lacked CES eligibility. Thus, he did not hold the position of AGMO in a permanent capacity or acquire security of tenure
in that position. Otherwise stated, his appointment was temporary and “coterminus with the appointing authority.”39 In Carillo v. CA,40 this Court ruled that “one who holds a temporary appointment has no fixed tenure of office; his employment can be terminated at the pleasure of the appointing power, there being no need to show that the termination is for cause.” Therefore, we find no violation of security of tenure when petitioner was replaced by respondent upon the latter’s appointment to the position of AGMO by President Aquino.
x x x."
