An autistic man is taking Sainsbury's to court for refusing to let him take his assistance cat into stores.
Ian Fenn, from London, said his inability to shop with his feline Chloe is limiting his ability to live an independent life, the BBC reports.
Mr Fenn, a designer and writer, said she helps him stay calm while in noisy public spaces, and has been in places including trains, buses, pubs and a hospital.
However, Sainsbury's argues that cats present a risk to food hygiene, unlike assistance dogs which do not.
Mr Fenn was told he needed to leave Chloe outside when he visited a Sainsbury's in Clapham, south London. He said the experience meant he stayed at home for two weeks afterwards.
He is now planning to take the supermarket giant to court for breaching the Equality Act 2010, which stipulates that business owners must make reasonable adjustments so people with disabilities are not severely disadvantaged.
"I get sensory overload in busy environments and tend to shut down, but with Chloe I can focus on her," Mr Fenn told the BBC.
"She brings structure to my life, she wakes me up in the morning, she tells me when to go to bed. It's difficult to know how she feels about the relationship, but I feel that we're a team now."
If Mr Fenn successfully argues that assistance cats are a reasonable auxiliary aid for disabled customers, and refusal of entry to assistance cats is contrary to the Equality Act 2010, this could set a legal precedent.
A Sainsbury's spokesperson said: "We want to be an inclusive retailer where people love to work and shop and understand that some of our colleagues and customers may need support in our stores. At the same time, safety is our highest priority and our colleagues are trained to balance maintaining our high food hygiene standards with supporting all our customers who shop with us.
“We are in contact with the local Environmental Health team to see if there are ways we can help Mr Fenn to visit our store without compromising this.”