Assistance dog handler here - am disabled.
uk law - no such thing as ‘emotional support dog’. Anyone can call their dog an emotional support dog - but it give them No RIGHTS to go anywhere what isn’t dog friendly.
ASSISTANCE DOGS (highly trained to mitigate persons disability and to behave appropriately in public) whether owner trained or charity trained have full public access rights to help the disabled person they support - hence can go in pubs, restaurants, theatres, concerts, shops etc that are usually ‘no dogs’
Any assistance dog causing an issue can be asked to leave if not behaving appropriately (e.g. if it peed in the shop or barking at people in a non alerting for emergency manner)
Assistance dogs have PUBLIC ACCESS rights to help the disabled person under the Equality Act.
Your house is not a public place - it is a private dwelling. No assistance dog has the right to cross your threshold without your permission as it is a private house.
Your MIL is trying it on big time and is totally unaware of the uk laws.
Really angers me people doing this -as gives us genuine handlers who rely on our dogs for safety and independence a bad name.
I would never expect my dog to go into someone’s house without their permission… it’s just plain rude and not them being ‘ableist’ or discriminating against me.
The mark of a good assistance dog is you don’t know it is there. They calmly lay at your feet alongside you - waiting to help but certainly are not causing havoc. The training is extensive so they are as unobtrusive as possible. They are obedient and calm.
You are totally within your rights to say no to her badly trained dog coming to your house whatever lable she choses to put on it…