How do I disable "purge selected items" in "recover deleted items" view

We have turned on deleted item retention and wish users to be able to recover items from deleted item retention but not delete items from that view.  There is a big "X" menu icon labeled "purge selected items".  We would like to be able to either disable use of this button or remove it completely from the view.  Is there a policy or reg hack to do this?  Or is there a way to modify the view itself to remove the display of this icon?