Short answer. No. The rule states that affirmative defences, if denied, shall not be the subject of a motion for reconsideration or a petition for certiorari, prohibition or mandamus. They may instead be among the matters raised on appeal after a judgment on the merits.
What the law says
Affirmative defenses, if denied, shall not be the subject of a motion for reconsideration or petition for certiorari, prohibition or mandamus, but may be among the matters to be raised on appeal after a judgment on the merits.
Rule 8, Section 12 — Affirmative defenses. Read the full provision →
Four remedies are closed off at once
The rule is unusually comprehensive about what is unavailable. A denied affirmative defence cannot be taken up by a motion for reconsideration, and cannot be brought to a higher court by certiorari, prohibition or mandamus. Listing all four together forecloses the usual workarounds, since a party denied one route would ordinarily reach for the next. The intended effect is that the case simply continues towards trial instead of pausing while the correctness of that one ruling is argued somewhere else.
The point is preserved, not lost
This is a restriction on timing rather than an extinguishment of the argument. The same sentence provides that the defence may be among the matters to be raised on appeal after a judgment on the merits. So a defendant who believes the court was wrong about venue, capacity to sue, jurisdiction over the person, the sufficiency of the cause of action, or a condition precedent keeps that objection intact. What changes is when it can be argued, which is after the case has been decided rather than in the middle of it.
Why the rule is built this way
Preliminary objections are among the easiest things in litigation to use for delay, because they can be raised early, decided quickly, and then challenged at successive levels while the trial waits. Closing off interlocutory review removes that lever. The rule accepts that a case will occasionally be tried in full when an early defence should have ended it, and treats that as the lesser cost when set against cases that never reach trial at all.
What to do in the meantime
Continue defending on the merits, and make sure the record is clear about what was raised and how it was resolved, because that record is what any appeal will be built on. It is also worth noting the discipline the rule imposes at the front end: affirmative defences must be raised in the answer, and failure to raise them at the earliest opportunity constitutes a waiver. A defence properly raised and then denied is preserved; one never raised at all is not.