The Labour leader has been a vegetarian for almost 50 years after working on a pig farm when he was in his early 20s.
Speaking to staff at an outlet of cosmetics retailer Lush, the 68-year-old said: "I eat more and more vegan food and have more and more vegan friends.
"There are quite a lot of vegan MPs - not a lot but there are some.
"One of my close relatives has just become a vegan and I went to her house for dinner and it was absolutely brilliant.
