Landlord says we have to declaw cats

So here's the story:

When we moved in we heard some tiny little meows, we came to find there were kittens outside. We saw a mom around so we didn't disturb them because they were still tiny. We put food out for the mom (usually not good but she looked so sleepy and I just wanted to help) about a week after we moved in I came home to find the mom was hit by a car. I scooped up the kittens and brought them in. We "nursed" them with canned kitten milk and they became a huge part of our family. They are now 6 months and our landlord knew we took them in. They are now demanding we get them declawed and have paperwork to prove it. I'm against declawing but if we don't we will not be able to keep them = do we do it or do we try to rehome them? I don't want to get rid of them; they're family. My heart is so torn.

**** update:

We need paper work stating they are declawed. I actually told them we could get the caps but they said they need proof. Our lease states "cats with terms and conditions" (or something along those lines)but since they didn't mention declawing when we told them I didn't think they would have us do it. 

****update again: we are bound by our lease until next year so we can't move. We didn't move in with cats so it's not like we were really looking to be accommodated??? Cats are being put down left and right at shelters and I'm afraid we won't find a home for the brothers to go to together. I'll discuss it further with my husband. They waited 6 months to mention declawing so it was kind of a shock honestly. :(