Starbucks has been forced to apologise after an arthritis sufferer was told she could not use a disabled toilet because she "did not look disabled enough".

Alexandra Austin, 41, and her daughter Lucy

Lucy Challis, 21, went to use the disabled toilet in Kingston’s Clarence Street branch at the junction with Eden Street, on Friday afternoon with mum Alexandra Austin, 41, who has chronic arthritis.

The pair, who live in Richmond, say they went into the cafe to buy a hot drink and a branded mug but also wanted to use the toilet.

Miss Challis said: "I asked for the key to the disabled toilet and the assistant looked at my mother and said ‘she doesn’t look very disabled.’ "It was disgraceful really. My mum has chronic arthritis and she needs me to help her in the toilet."

The care agency supervisor said the confrontation has put her off going to Starbucks and she plans to protest outside the shop next week.

Miss Challis said: "I asked to speak to the manager but he just didn’t care. He just said that English was not the assistant’s first language but I don’t see why that should matter.

"If you are disabled you are disabled.

"We just wanted to go to the toilet before getting a coffee, sometimes you need to do that.

"I was going to buy my mum a mug to add to her collection but not anymore. They can’t get away with treating people like that.

"I’m going to protest outside the shop because I think people should know that this is how they treat disabled people."

In June the international coffee shop chain, which operates 549 stores in the UK, was awarded full marks in a disability equality index survey in the United States by the American Association of People with Disabilities.

A spokeswoman for Starbucks UK said: "We have investigated this matter and would like to pass on our apologies to the customer affected. Our toilets are always available for our customers use."

Tolworth disability campaigner Adam Lotun said: "More comprehensive staff training needs to be done.

"There are many disabled people who are not mobility impaired but need to use disabled toilets."