On Wednesday, the broadcaster and the show's other panellists paid tribute to their guest Pamela Anderson by dressing like her character C.J Parker from TV show Baywatch, in a segment they jokingly called "Grey Watch".
While Janet and Denise Welsh opted for the skimpy swimsuits, Andrea McLean and Gloria Hunniford both rocked a red shirt and shorts, which the male characters wore on the series.
Andrea commented: "If you’re shocked, that’s the first time we’ve seen this, so we feel the same as you do!"
WATCH: Janet Street-Porter apologises on Loose Women
Janet then surprised her co-stars further by announcing that she would keep her outfit on, standing up to reveal that she was still wearing the flattering costume.
She said: "I kept my outfit on," going on to joke: "I said yesterday I would be wearing a swimsuit and our editor nearly fell on the floor."
With her long legs and fabulous figure, the 73-year-old prompted plenty of compliments from viewers who loved her body confidence.
Janet paid tribute to the show's guest, Pamela Anderson
"Fabulous," one commented. Others added: "She is 73 and looks fantastic," and: "Go on girls!!! Absolutely LOVED this!!!!!"
Veteran journalist and presenter Janet previously shared that her secret to keeping trim was to follow a royally approved diet.
On Loose Women last year, the star admitted that she follows a very similar eating plan to Prince Charles.
After a discussion of the Prince's eating habits, Janet said: "Prince Charles and I have a lot more in common than I thought, because, with the exception of the alcohol part of the diet, that's how I eat - all the time, small amounts."
She continued: "We're more or less the same age and we have pretty fit routines. I know he likes walking, and I like walking, and so on…"
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