There is only one WY to be able to say no. Be ready to walk away. Then you can just be honest and see what happens. You may find out you have more margaining po

There is only one WY to be able to say no. Be ready to walk away. Then you can just be honest and see what happens. You may find out you have more margaining power than you thought. You may find out you had none. But if you aren't ready to walk away or be fired, you are never going to be able to justify and positions besides just saying yes.