Sainsbury's has apologised after one of its stores placed an advert calling for an artist to decorate the staff canteen for free.
The store in Camden Road, north London, said it was looking for an "ambitious artist to voluntarily refurbish our canteen".
It said the artist would gain experience in the creative industry while making "a comfortable area for our employees to escape to".
The advert, placed in the latest edition of the Camden New Journal, sparked a backlash on social media.
Artist Conor Collins posted a letter to the supermarket chain on Twitter. He wrote: "I am looking for a company worth £150,000,000 to feed all of my artist friends in Manchester."
In the post, he suggested the company "take some of the millions you fork out to your CEOs and pay for someone to do work for you so that the concept of 'starving artist' wouldn't have to be a thing".
Paul Johnson Rogers, a British composer, tweeted that the store was "disgusting" and "should be ashamed".
The advert said the artist could "bring their own style to transform our canteen into an environment that allows positivity and inner peace through the scopes of your imagination".
"By crafting your ideas into a reality for our company, you are recreating what is originally a basic canteen to salvage the energy of our staff members."
A Sainsbury's spokeswoman apologised for the store's "error of judgment" and said it was in talks with the store.
"We're discussing this with our store in Camden. The advert was placed in the local paper following a colleague discussion around ways to improve the canteen and offer an opportunity to the local community.
"It is not our policy to hire volunteers and we are sorry for this error of judgment."