Tesco, whose most popular vegan sandwich is a falafel and hummus wrap, saw a near-75 percent jump in its plant-based sandwich sales compared to last Veganuary, while Sainsbury's also recorded a 35 percent increase.
Waitrose' vegan wraps, salads, and snacks are also reported to be up by 20 percent compared to last year.
According to The Guardian, food-to-go Buying Manager at Tesco Cate May said: "Thanks to some great recent quality innovation in vegan wraps and sandwiches we are now seeing the emergence of a dedicated lunchtime plant-based shopper.
"Until now most of the noise for vegan food – understandably – has been for meat-free alternatives to classics like burgers, sausages, and steaks.
"However, the rise of veganism and flexitarian diets will continue to have a major impact on the takeaway lunchtime market and choices available."
The soar in vegan sandwich sales has been credited to Veganuary's 'astounding' success.
This year, a record-breaking 400,000 people signed up to the month-long pledge to ditch animal products from their diet, including Dragon's Den star Deborah Meaden and Queen icon Brian May - who has recently announced he will stay plant-based during February too.