How to ban pets within the law

General Discussion

I know the government has made it illegal for LLs to have blanket bans on pets, but they allow LLs to provide reasonable grounds to refuse them.
What if your AST stipulates this in a clause so the tenants don't bother asking if they can have a pet in the first place mid-tenancy.
For example:
“No free roaming pets are allowed on the premises due to the potential damage that can happen which could run into tens of thousands of pounds which would not be covered by insurance."
(I know it would be worded better but you get my point)

If you think that clause would not hold up in a court then what other clause would help? Just a clause saying that the tnt needs permission from LL? Then just no every time? Isn't there any other way at all?