This is a confusing. The aircraft is in TUIfly (Germany) retro Hapag-Lloyd livery but is being operated by Sunwing Airlines (Canada) on summer lease to Thomson Airways (UK). Back from winter lease to Sunwing in Canada but seems to be sub-leased back to Thomson Aws and operated by Sunwing instead, as the Canadian registration and the big Canadian flag on the nose would seem to suggest.  It's based in Dublin (DUB) for summer 2012.
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/kenfielding/">Ken Fielding</a>
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/kenfielding/7273394216/">Flickr - C-FTLK 1 Boeing 737-8K5W Thomson Airways (Sunwing Airlines) PMI 26MAY12</a>