The pregnant F1 heiress and socialite was joined by her husband Jay Rutland at Park Lane's Intercontinental Hotel for a Formula 1 charity photographic auction.
Mum-to-be Tamara accessorised her monochrome outfit with a black blazer, clutch bag and a pair of gold and black stilleto heels.
Tamara'sbillionaire father Bernie Ecclestone also attended the event, as did celebrity chef James Martin, presenter Vanessa Feltz and former F1 racer, Damon Hill.
Posing for photographs, grandfather-to-be Bernie, 83, stood with his 29-year-old daughter, who is almost eight months pregnant.
Last month Tamara revealed that she and husband Jay are expecting a baby girl, when she posted a photo of a little jewel-encrusted gold rattle, nestling in a pink box.
"'The most beautiful baby shower invites I have ever seen, I have the world's best sister," wrote Tamara – thanking Petra Eccleston, who organised the event for her expectant sister.
Tamara announced her pregnancy in a world exclusive with HELLO! magazine in September, telling readers: "I just feel so lucky".
She was delighted to share news of her and Jay's "honeymoon baby" just four months after the couple tied the knot in a lavish French Riviera wedding, just nine months after meeting the former City stockbroker.
"I never imagined this all happening so quickly. It's crazy how life works in such mysterious ways. Jay loves children and I'm really excited for the next phase of our relationship," she told HELLO! at the time.