Thomas Cook to fly 1x weekly between Gatwick and Lemnos in Greece on Mondays for summer 2020. The TC website lists it in the timetable but looks like flights have not gone on sale yet
https://www.thomascookairlines.com/e...able_S2020.pdf
London-Lemnos is currently flown solely by charters - 1x weekly BA from Heathrow for Mark Warner and 1x weekly by Enter Air from Gatwick for Sunvil
Kavala (Greece), Naples (Italy) and Holguin (Cuba) are flown in S19 but are not currently listed in the S20 timetable