Luisa, who runs her own cake business, joined the Ice Cream Alliance on a rally in London, which saw 10 trucks drive in convoy around Parliament Square with their cheery chimes tinkling.
Dressed in a bright red figure-hugging frock with cutout detail around the neckline, which she teamed with nude peep-toe Louboutins, Luisa showed her support by clutching a placard reading: "Save our nation's ice cream vans. Buy a cone today!"
Since the 70s, ice cream van numbers have dropped from 25,000 to just 5,000 due to competitive supermarket prices and increased red tape. As a small business owner herself, Luisa feels strongly about the issue.
Luisa, who is set to launch her next venture - Bakers Tookit - in the coming months, said: "I'm happy to get behind the campaign as I'm a big supporter of small businesses.
"For a lot of people the ice cream van brings back brilliant childhood memories, it would be a shame to see that go. Plus who doesn't love ice cream!"
Meanwhile, Luisa is also said to be in talks to host her own baking show with Food Network. Given her advert for Bakers Tookit in the Apprentice final, we think she'd be perfect for the job!
Do you support Luisa and the campaign? Tell us below, as the best comment from across the website each week wins £50!