I recently flew with Jet2 to Lanzarote on their leased A330, whilst onboard the cabin crew were talking about a 2nd A330 joining Jet2 for 2019 which is confirmed by Jet2. But, during the flight whilst waiting for the lavatory the captain (who was also waiting thanks to slow passenger

) & crew were talking about the 2nd leased A330 might not be from Air Tanker due to commitments with Thomas Cook amongst others.
As the flight deck crew are Air Tanker employed might be some truth in it.... but if not Air Tanker who would Jet2 use for their 2nd A330.