HER PAST HAS COME BACK TO HAUNT Dimitra Liani-Papandreou, and it is alternately amusing and scandalizing her fellow Greeks. Since marrying the aging Andreas Papandreou in 1989, the former Olympic Airways flight attendant has grown accustomed to criticism and seemed impervious to the attacks on her increasing influence as chief of staff for her husband, the Prime Minister. She remained silent when the leftist Athens daily Avriani began splashing its pages last August with pictures of a topless, sunbathing Mimi, as she is known, frolicking in the sun during the carefree days of high flying. But when Avriani's publisher, George Kouris, ran a front-page photo--widely reported to be a montage--of her on a Greek island in an intimate pose with another naked woman, an enraged Liani-Papandreou, now 41-ish, went on TV to defend herself. "I have done no harm to anyone," she told viewers. "No citizen has been as humiliated as I."

More interesting to political observers than the self-defending outburst was Liani-Papandreou's reply to a question about her political future: "I will decide when the time comes." And then she added, "Should I not enter politics because I once bathed naked?" Ever since Papandreou divorced his wife of 38 years to wed his Mimi, she has come under fire for interfering in government, screening access to the Prime Minister and summoning ministers for meetings. In recent months criticism has intensified. Long-term members of Papandreou's Panhellenic Socialist Movement (PASOK) blame her for their exclusion from the Prime Minister's inner circle, complaining that she has replaced them with the so-called loyal royal court, which includes her entourage of friends, two Orthodox priests and an astrologer.

The lack of a clear answer about her blond ambition deepened divisions in the Prime Minister's ruling party and fed fears that her increasing influence could undermine it. "A web of power has been woven around the Prime Minister," says former European Commissioner for Social Affairs Vasso Papandreou, who is no relation. "It operates outside the institutions and has a paralyzing effect on the party and government." Still, while party dissidents issue dire warnings about the fallout if Liani-Papandreou runs for office in national elections scheduled for 1997, close associates confirm that the ailing Prime Minister, 76, would do anything for the woman who spends her days looking after him.

As Papandreou becomes more dependent on her, many PASOK members believe he could conceivably appoint her his successor as leader of the party he has ruled for two decades. In another scenario, Greek politicians speculate, he could make her an honorary parliamentary member. Says party deputy Theodoros Katsanevas, who is Papandreou's son-in-law: "One fine morning we will be told there will be elections in 40 days, and she will be put forward as a candidate on the honorary deputies' list." If the frail Papandreou dies or is forced to retire before perhaps handing over the reins of government to his sun-worshipping wife, many speculate that she will try to grab power herself. In the meantime, media baron Kouris claims to have more photographs of Mimi baring all, as well as a sizable file of material about alleged corruption that he promises will spoil any political plans she may be hatching.

--Reported by Anthee Carassavas/Athens