How about I stop a man from hiring staff?
Are you kidding? Why do you want to stop him from hiring staff?
I think that he's already got enough workers in his company.
You shouldn't stop people from hiring in their own business. You don't have a say on what people do with their business.
I can't stop him myself. I'm going to call the labor board on him for hiring too many people.
You are allowed to call but you cannot do anything else to stop him from hiring people. Let the board decide whether he is allowed or not.