I think Airtours do as well. I would have thought any tour operator flying from Newcastle would offer the option of a 21 day holiday. If you look at the brochures they usually do. I would book up as soon as possible though because the flights are selling.
We wanted to go on 1st July next year and went to book on 10th August. The hotel we wanted was already booked up from mid June to mid July. We ended up booking it for 15th July and when I have checked on the net you can only stay in the hotel for a fortnight from the end of August now. However, this is for a particular hotel but it just shows you how quickly it is getting booked up.