Wetherspoon boss Tim Martin has stood by the firm's policy on guide dogs after the Equality and Human Rights Commission (EHRC) said it could be illegal.
The popular pub chain has had a longstanding ban on dogs, with the exception of guide dogs, but more recently introduced a policy insisting those with a guide dog produce ID from Assistance Dogs UK (ADUK).
The BBC reports it has spoken to a number of disabled people who have been refused entry to Wetherspoon pubs with their assistance dog due to not having ADUK identification, with one woman left feeling "sick and humiliated".
The EHRC has now written to Wetherspoon to voice concerns about whether the policy complies with UK law.
But Wetherspoon chairman Tim Martin said the policy was necessary to prevent "an increase in dog incidents", as opposed to following the ADUK guidance which asks pub staff to make a judgement call on whether a guide dog is trained and safe once it is already inside the premises.
Martin said: "This is a complex area for pubs and other organisations. The interests of those with disabilities need to be protected while, at the same time, employees and the public have to be protected from a substantial increase in dog incidents.
"The BBC article , unfortunately, did not explain Wetherspoon's broader legal responsibility for the safety of its customers and staff, which we set out in detail for them, and which is the reason for our policy.
"ADUK is an organisation which itself demands high levels of training for assistance dogs, for which it issues documentary proof.
"Yet it is offering, in effect, legal advice to the public, which states that pub companies should not ask for documentation.
"Instead, according to ADUK, pub staff should be asked to make a judgement, after a dog is already in the pub, as to whether it is trained or not.
"It is inevitable, as a matter of common sense, that ADUK's advice, if followed, will lead to an increase in dog incidents in pubs, and may already have done so, in the absence of sensible checks in advance of entry.
"In contrast, Wetherspoon's policy clearly provides greater protection for employees and the public, and is consistent with established regulations in areas such as proof of age in pubs and blue badges for parking.''
ADUK chief executive, Vicky Worthington, told the BBC Wetherspoon had approached the charity for guidance before establishing the policy, but added: "Sadly they didn't take on board any of the advice we provided."
A spokesperson for the Equality and Human Rights Commission told the BBC: "We are aware that a significant number of disabled people with assistance dogs have been refused entry from JD Wetherspoon venues because they aren't carrying formal identification for their assistance dogs."
"We have written to JD Wetherspoon to ensure they are aware of their duties under the law."