Taoiseach Leo Varadkar has described a video on behalf of Fine Gael's Wexford candidate Verona Murphy as "kind of bizarre" and not approved by party headquarters.
The video referred to "character assassination" by media of the candidate who provoked widespread criticism following her controversial comments about migrants.
Mr Varadkar said he had only seen the video on Friday evening.
“I have to say I thought it was kind of bizarre but it wasn’t approved by the party,” he said.
“I’m not sure if it was approved by the candidate but as I say it will form part of the review that we will carry out in all four constituencies in the next couple of weeks, as we always do.”
“It’s the normal course of events that after a byelection we carry out a review of each contest and review the ticket on that basis,” he said.
“So it’s always in the power of our executive council on my recommendation to add candidates or delete candidates,” he told media at the Dublin Mid West byelection count in Adamstown.
Asked to clarify if all candidates would not be guaranteed a place on the ticket at the general election, Mr Varadkar said:
“That’s correct. But I wouldn’t like that to be misunderstood or misrepresented under the normal course of events under our party rules,” he stressed.
“After an electoral contest we review the result. And it is always open to the executive council on my recommendation to add candidates or delete candidates.”