What if the person will not provide blanket permission?
Public Relations generally only uses a photo if it can obtain blanket permission for its use. This practice is recommended because it can be unwieldy to keep track of the many permitted uses. Although specific permissions are discouraged for this reason, you are free to obtain them if you wish. (This is another reason you may not copy and use photos from other UK web sites without verifying that a consent form exists, in a few instances, consents are very limited).