Facts,
Have you got the right airline? I'm not aware of Thomson having any Eastern European A320 on lease? Thomas Cook have, which are the Avion Express and Smartlynx aircraft, but Thomson don't.
All of Thomson 3rd party flying is not leased in equipment, it's the host airline using their own aircraft, flight crew, flight numbers and so on. These are airlines like Freebird, Air Europa, Norwegian and Air Malta.