An angry Capt. Mark Phillips, husband of Britain's Princess Anne, has denied an Australian newspaper report that his marriage to Queen Elizabeth II's daughter is in trouble.

When asked Sunday night if the report in the Sydney Sunday Telegraph was unfounded, the 32-year-old cavalry officer snapped: "Yes. You should know better than to even ask me."

The Sydney newspaper said the queen was upset by rumors that her daughter's marriage of nearly eight years was on the rocks, particularly by reports of a "close relationship" between Phillips and a "television personality."

The paper did not identify the woman. But Angela Rippon, who became popular as the British Broadcasting Corp.'s first female newscaster, is writing a book about horses with Phillips and has stayed several times at Gatcombe Park, the Phillipses' home in Gloucestershire southwest of London. She was quoted by the Sun newspaper in London yesterday as denying she was the "personality" in question.

The Sun quoted the newscaster, who is married to businessman Christopher Dare, as saying, "The marriage of Princess Anne and Capt. Phillips is one which does not show even the slightest sign of a hairline crack, let alone of breaking up."

Last year, Los Angeles Dodgers first baseman Steve Garvey and his wife Cyndy went to court to protect the image of their marriage. Now they have separated and plan to seek a divorce.

The first indication of their marital difficulties surfaced last summer in an article in Inside Sports titled "Trouble in Paradise" that quoted Cyndy Garvey at length. The Garveys charged that author Pat Jordan had used the quotations -- which suggested that Garvey's baseball absences were causing problems between the couple -- grossly out of context to exaggerate their difficulties. The couple sued the magazine, and an out-of-court settlement was reached earlier this summer.

The couple also tried unsuccessfully to prevent the Los Angeles Herald Examiner from serializing the article. The rumors of troubles persisted, however, including reports that Mrs. Garvey has been seeing songwriter Marvin Hamlisch.

In a brief statement Friday, the couple announced their breakup after 10 years of marriage. Lee Solter, whose public relations firm, Solters and Roskin, issued the announcement for the couple, said a divorce "was in the works" and that he knew nothing of the settlement that will have to be reached.

It was a pleasant evening with political overtones. The honoree, Colorado state senator Polly Baca-Barragan, couldn't attend the awards ceremony as part of National Hispanic Heritage Week last night at the Washington Hilton because she was embroiled in a reapportionment battle back home.

So Barragan's sister, Betty Baca, accepted the award for bringing Hispanic women into the political arena. About 90 guests raised their wine glasses in a toast to Barragan as Lu Betancourt, chair of the Hispanic Caucus of the National Women's Political Caucus, handed Baca the award.

"Polly is proud of the Hispanic Caucus of the National Women's Political Caucus because of the aggressive posture taken on feminist issues such as the ERA," she said. "It's time to recommit ourselves to feminist goals."

Deputy White House Press Secretary Larry Speakes celebrated his 42nd birthday yesterday with a visit from President Reagan and a telephone call from hospitalized press secretary James Brady.

At first, Speakes did not recognize Brady's voice and said, "Who is this?"

"It's The Bear," Brady replied. Brady's friends call him "Bear."

Reagan, in his visit, told Speakes: "I hope I look as good as you do when I get to be your age. Happy Birthday."