@Buttercup77 - I have a legal background and I think (but could be wrong) that this is very unlikely to fall under the disability discrimination act. I think people are forgetting that wearing a mask is not solely for the wearers benefit but for the collective benefit of society during a pandemic. The mask isn’t just to protect you from getting Covid but to protect other people if it is indeed the case that you yourself have it.
Your legal background must have been a while ago, it's been the Equality Act for 10 years now.
A blanket 'no mask - no entry' rule with no exceptions would amount to unlawful indirect disability discrimination.
Indirect discrimination is where you have the same rule/way of doing things for everyone but it disproportionately disadvantages people with a certain protected characteristic - in this case disability.
Indirect discrimination can be lawful if it is a proportionate means of achieving a legitimate aim, which I think is what you are suggesting.
There is no doubt that preventing the spread of covid is a legitimate aim but a blanket rule with no exceptions cannot be considered a proportionate means of achieving it.
This is because face coverings are one tool among many that can make a small but significant difference. They can help make a bigger difference in combination with all the other measures but on their own they are not a gamechanger.
OTOH a blanket face-covering rule would completely exclude many disabled people from accessing goods and services, including public transport, altogether. That's a game changer.
So it's not proportionate and it's not lawful.
Providers of goods and services have a legal duty to provide reasonable adjustments for disabled customers and service users. It's a way of mitigating indirect discrimination and enabling as many people as possible to access your goods and services. Exceptions to a 'no mask - no entry' rule for people with disabilities are a reasonable adjustment. Providers that fail to provide reasonable adjustments, either through malice or ignorance, should expect to be sued.
Providers of goods and services are also prohibited from harassing customers and service users. Harassment is any unwanted conduct related to a protected characteristic that violates your dignity, or creates an intimidating, hostile, degrading, humiliating or offensive environment for you.
So while it may be reasonable for providers to check whether you have a valid reason to enter their premises without wearing a mask, they should do so in a sensitive manner. None of the people behind you in the Tesco queue or the bus queue have the right to know that you even have a disability, let alone any of the details, and you should not be asked any unnecessary, intrusive questions. A simple statement of 'I have a disability/condition that prevents me from wearing a mask', delivered out of earshot of the rest of the queue, should be enough. If it isn't then OP is right, there must be an official scheme to enable people who can't wear masks to go about their daily business without harassment.
A sign in a shop window can constitute harassment on its own. If you put a sign up saying 'no mask - no entry' or worse, 'no mask - no entry - no excuse' then you are creating exactly the type of environment for disabled people that the Equality Act defines as unlawful harassment.
It doesn't matter if the provider didn't intend to harass disabled people. They might have done what they did with the very best of intentions but the EA says that harassment is any unwanted conduct that has the purpose or effect of ...
So to avoid the danger of being taken to court, providers of goods and services should listen to disabled people when they say that something a provider has done has made them feel intimidated, degraded, or humiliated, or that their dignity has been violated, or that a hostile or offensive environment has been created for them because of something the provider has done. And they should put it right.
And if a lot of people who can't wear masks are saying they will just stay at home and not even attempt to access the goods and services - that they have the same right to as anyone else - because they just can't face the nastiness, then providers need to listen really hard because this is a sign of abject failure on their part.
And if anyone else has a problem with someone not wearing a mask then they should take it up with the service provider, not the other customer.
If there are lots of people not wearing masks despite the stated policy then you may have a genuine complaint but it will be very general - 'why are you letting so many people in without masks?'
If there are few enough people not wearing masks that you have singled out an individual and decided to complain about them then you should be shown the door and not allowed back.
Providers of goods and services have a duty to prevent creating a hostile environment for their customers and service users and if you are part of that environment then they have a duty to not condone your bullshit.
TL;DR: The Equality Act has not been cancelled because of coronavirus.