Here's a link for the UK Psychological Assistance Dogs UK

And another: Assistance Dogs (UK): A voluntary coalition of assistance dog organisations

They aren't called Emotional Support Animals in the UK, so it appears...perhaps "Psychological Assistance Dog" is more correct.

IF for some reason you still can't find how to make this happen under that... why not train the dog as a service dog instead? I'm sure he already does things for you that qualify! Then you can have more freedom.

Good wishes. If you need more help searching, let us all know!