Short answer. Yes, on both counts. Rule 79, Section 4 of the Rules of Court lets any interested person file a written opposition contesting the petition — either because the person seeking letters is incompetent, or because you have your own right to the administration — and pray that letters issue to you instead.
What the law says
Any interested person may, by filing a written opposition, contest the petition on the ground of the incompetency of the person for whom letters are prayed therein, or on the ground of the contestant's own right to the administration
Rule 79, Section 4 — Opposition to petition for administration. Read the full provision →
What the law says
may pray that letters issue to himself, or to any competent person or persons named in the opposition
Rule 79, Section 4 — Opposition to petition for administration. Read the full provision →
The two grounds for opposing
Rule 79, Section 4 recognises exactly two grounds. The first attacks the petitioner: the incompetency of the person for whom letters are prayed therein — that the relative asking to administer the estate is not fit for the trust. The second asserts yourself: the contestant's own right to the administration — that as between the two of you, the law prefers you for the appointment. The grounds are not mutually exclusive; an opposition can argue both that the petitioner should not be appointed and that you should be. What the section does not allow is opposition by a stranger — the opponent must be an interested person, someone with a stake in the estate.
You can ask for the appointment yourself
The opposition is not merely a veto. The oppositor may pray that letters issue to himself, or to any competent person or persons named in the opposition. That last clause matters in family disputes: if you do not want the burden of administering the estate but trust a sibling, an in-law or a professional more than the petitioner, you can name that person in your opposition and ask the court to appoint them. The court is then choosing between candidates, not just ruling the petitioner up or down — which changes how you frame the contest. An opposition that offers the court a competent alternative is a different proposition from one that only objects.
It must be in writing, and it must be filed
The section is precise about form: opposition is made by filing a written opposition. Turning up at the hearing to object orally, or writing to the judge, is not the mechanism the rule provides. The written opposition is filed in the settlement proceeding itself, where it puts the contest on the record and makes you a party to the fight over the appointment. Practically, that means the petition your relative filed will carry a hearing date, and your window for acting is before the court hears and grants it. Once letters of administration have issued, you are no longer opposing an appointment — you are seeking to undo one, a steeper climb.
What strengthens an opposition
Whichever ground you invoke, particulars beat adjectives. If you contest the petitioner's competency, be ready to show the facts behind it — the conflict of interest, the mismanagement, the circumstances that make them unfit for the trust. If you assert your own right, establish your relationship to the deceased and your stake in the estate, since both your standing as an interested person and your claim to preference flow from them. Bring the documents a court would want: proof of filiation or marriage, and anything showing your involvement with the estate's assets. A lawyer can then match your position against the order of preference the courts apply in choosing administrators.