Following are some ideas how you can you say “No!” without saying “No”:
1. Acknowledge the importance of the request.
“I understand why that’s important to you.”
2. Inform the person that you have a problem with it.
“But I have a problem with it.”
3. Describe the problem as you see it.
“Your doing that would mean it would put a burden on everyone else.”
4. Elicit from the person something else.
“Let’s think of something that would be fair to everyone.”