Pretty easy as it’s a breach of contract if you didn’t declare you ran a business from home when you signed the contract - it’s immaterial that you’re working as an escort. Either way, they will need to provide proof rather than make the accusation, although that said, if a neighbour does complain to your landlord, they might already have enough evidentiary support.
Also, I believe a landlord can evict you for any reason whatsoever, but it is a lengthy process. Or if there’s a break clause in your contract, they can just give you two months notice. Either way, I advise you contact Shelter or CAB as they will be better placed to advise.