Hmmm, on further investigation, parliament.uk's images are not its own - their
copyright page states
"All photographs of individual MPs and Peers on the biographical pages and Committee
pages are the exclusive property of Dods and are protected under international copyright
laws. The photographs may not be reproduced, copied, stored or manipulated in any form
without the written permission of Dods unless for non-commercial purposes, provided
permission is sought beforehand and the photo is credited. For more information on these
photos, please email editor(a)dods.co.uk "
Obviously this isn't the case, but does indicate a barrier to Parliament releasing the
images.
Chris