BEAUFORT, S.C.— Facing continued scrutiny of his personal life, Newt Gingrich on Thursday called an interview by his ex-wife Marianne Gingrich “tawdry and inappropriate,” and refused to answer any questions about it.

View Photo Gallery: The former House speaker is seeking the Republican presidential nomination.

“I’m not going to say anything about Marianne,” he said, as his current wife Callista stood a few paces behind him at a campaign rally here.

Gingrich on Thursday nabbed the endorsement of Texas Gov. Rick Perry as Perry dropped out of the GOP presidential race, but his momentum could be affected by his second wife’s decision to speak out.

In the ABC News interview scheduled to air Thursday evening and in an interview with the Washington Post, Marianne Gingrich says that the former House speaker asked her for an open marriage while he was having an affair with his current wife, Callista, who has been a constant presence on the campaign trail.

Marianne Gingrich told the Post’s James V. Grimaldi that her then-husband asked her for an “open marriage” or a divorce at the same time he was giving speeches around the country on family and religious values, his former wife, Marianne.

Newt Gingrich on Thursday referred to comments by his two daughters from his first marriage, Jackie Cushman and Kathy Lubbers, who wrote an open letter to ABC News:

“The failure of a marriage is a terrible and emotional experience for everyone involved. Anyone who has had that experience understands it is a personal tragedy filled with regrets, and sometimes differing memories of events,” the letter stated. “We will not say anything negative about our father’s ex-wife. He has said before, privately and publicly, that he regrets any pain he may have caused in the past to people he loves.”