Sir Paul McCartney wants people to banish meat from their diets once a week.
The 74-year-old rocker - who has been a vegetarian for around 40 years - has released a booklet with his some of their close friends for his Meat Free Monday campaign, which he started in 2009 and encourages people to skip animal products for at least 24 hours each week, for a healthier, greener diet for 2017.
Paul said of the campaign: "We tend to think that what we have always done is what we always will do in the future. How boring is that? Can't you look at your life and go, 'You know what? I think I might fancy a change.'"
Kevin Spacey - who is an advocate for animal adoption - has been begged to turn vegetarian on numerous occasions and has now jumped on the bandwagon.
He explained: "Having one designated meat free day each week is an easy way to help protect the planet. There's nothing to lose by supporting Meat Free Monday but a great deal to gain."
Vivienne Westwood - who is an animal rights activists and uses faux fur in her designs - added: "I believe meat has so many toxins in it that your body never really manages to get rid of them. People believe that you have to have protein and bulk to give you energy, but fruit and vegetables are full of health.
"Your body processes these efficiently so they do the maximum good for you. You feel so well, light, supple, and full of energy."
Joanna Lumley, 70, has also decided to embrace the new lifestyle after being inspired by the campaign in a bid to save lives and help the planet.
He said: "Just see how easy it will be not to eat meat for one day a week. Just think how the world will benefit from fewer trees being cut to make way for grazing animals. Just imagine how many lives, both animal and human you will help to save: and join the fab Paul McCartney and millions more, including me, in making Monday a Meat Free day."