A Waitrose spokesperson told Plant Based News: "Each April and September we revamp our seasonal lines, and this was one of them. It contains a cheddar style vegan slice with juicy tomatoes, vegan mayonnaise and sweet pickle on malted bread."
According to Waitrose, the sandwich, which currently retails for an introductory price of £1.95, will go up to its regular price of £2.60 on the September 19.
It follows the stores existing plant-based sandwiches: the Vegan Sweet Potato & Ratatouille Sandwich and Waitrose Good to Go Vegan Mexican Butternut Squash Wrap.
Waitrose has launched a signficant number of vegan-friendly products in recent months in a bid to keep up with growing consumer demand. Earlier this Summer, the store launched a dedicated vegan section.
Speaking at the time, Chloe Graves, Waitrose Chilled Vegetarian and Vegan Buyer, said: "Our current selection of products has been selling really well week after week, with requests for more choice coming from our customers and partners, so we could clearly see there was an appetite to have more vegetarian and vegan options in our shops.
"Increasing our range builds on the work we did last year to increase choice for our customers in this area. We are working with some fantastic exclusive brands to ensure our shoppers have a really unique selection of food to choose from."
This story was updated on September 6 with additional information from Waitrose.