Princess Michael of Kent has revealed that the economic downturn has forced her to make cutbacks - giving up restaurants for dining at home.
The outspoken Marie-Christine said that when entertaining friends at her Kensington Palace apartment, she cooks and also gets in "help".
Princess Michael, who is married to the Queen's cousin, made her comments in an interview with The Times to promote her first historical novel, called The Queen Of Four Kingdoms.
She said: "I am in very austere economic times too, thank you very much. We've cut back dramatically.
"I mean, we never go out to dinner unless we go to somebody's house. We never go to restaurants. That's too extravagant. We invite people here. I cook. Well, if I'm giving a dinner party I get in help."
Since 2010 Prince and Princess Michael have been paying the full commercial rent of £120,000 a year on their plush five-bedroom accommodation at K ensington Palace, which features a walled garden, roof garden and courtyard designed by Sir Christopher Wren.
The Queen paid the rent on their behalf for seven years after a parliamentary row erupted in 2002 when it emerged they paid only a peppercorn rent, rumoured to be just £69 a week, for the apartment they have used for more than 30 years.
During the interview, Marie-Christine joked that she could write a version of the erotic literary hit Fifty Shades Of Grey.
Asked if her new book was racy, she replied: "No, not at all. I am not going to write Fifty Shades Of Royal Purple. Well, I could, but I would be put in a a beautifully decorated - that having been my profession before - room in the Tower."