Eastern Europe from CWL
This is a list of UK airports handling 3 million passengers a year at the top to to 500,000 passengers per year at the bottom. I've highlighted those airports with connections to Eastern Europe:
BHD - No flights to Eastern Europe - Airlines might have operational problems operating from here.
SOU - No flights to Eastern Europe - Airlines might have operational problems operating from here.
JER - No flights to Eastern Europe - Airlines might have operational problems operating from here.
CWL - No flights to Eastern Europe
DSA - Focus city for Wizz Air, will see 30x flights a week to 9x destinations.
SEN - EasyJet and Flybe operate to PRG and BUD
EXT - No flights to Eastern Europe
INV - No flights to Eastern Europe
GCI - No flights to Eastern Europe - Airlines might have operational problems operating from here.
IOM - No flights to Eastern Europe - Airlines might have operational problems operating from here.
PIK - RYR Base - will see 2x flights a week to Rzeszów
BOH - RYR Base - will see 2x flights a week to Krakow
NWI - No flights to Eastern Europe
Only four of these airports in the above list see flights to Eastern Europe this summer; Doncaster-Sheffield, Southend, Glasgow-Prestwick and Bournemouth.
Prestwick and Bournemouth are the only airports in this list with RYR bases so unsurprisingly have a small number of flights to Poland.
Southend is a primarily a London airport, with great connections to (East) London and therefore has an enormous catchment area. It sees 3x flights to Budapest a week with Flybe and and 11x flights to Prague per week (4x with EasyJet and 7x with Flybe).
Doncaster-Sheffield is a focus city for Wizz Air and has 30 flights per week to 5x cites in Poland, 2x cities in Romania, 1x in Latvia and 1x in Lithuania. I assume there must be a large population of Eastern-Europeans living in the catchment area which will be some of the reason for the number of flights. I know that Boston in Lincolnshire was named as having a large number of Poles living there in the 2011 census? I'm sure others can explain this more than me.
I've drawn up a table of all the routes and flights to Eastern Europe from airports outside of London. There is far too much data to give on here so instead I'll just focus on Poland for now.
Poland has the largest number of flights per week from airports in the UK outside of London. It is the most likely country that CWL would see a route to in the future. However, only four airlines operate routes from the UK outside of London to Poland; Ryanair, Wizz Air, easyJet and Jet2.
Ryanair operates 128 flights per week on 50 routes to Poland from UK airports outside of London.
Wizz Air operates 45 flights per week on 14 routes to Poland from UK airports outside of London.
easyJet operates 17 flights per week on 5 routes to Poland from UK airports outside of London.
Jet2 operates 6 flights per week on 3 routes to Poland from UK airports outside of London.
Jet2 and easyJet only operate from their own bases in the UK to airports in Eastern Europe. Ryanair are the same however it does operate to NCL and ABZ which are not bases to various destinations in Eastern Europe. Wizz Air therefore are the more likely contender to open up a new route to CWL, but with the many sensible posts on this it seems unlikely given their presence in BRS and the large competition in BRS from EZY and RYR (in the below list you can see BRS has the highest number of flights per week to Poland from anywhere outside London except for Liverpool).
Krakow and Warsaw see the most flights from the UK followed by Gdansk and Wroclow. I'd say Krakow would be the most likely contender given the large numbers of tourists drawn there. If flybe were to base a forth aircraft in CWL in 2019 then another options could be PRG and BUD given they operate these routes from SEN currently. These destinations would more likely be outbound tourists to these cities rather than migrants going to and from home however so would fair similar to Berlin and Venice for example.
Just a quick run-down of which UK airports outside of London see the most weekly flights to Poland:
For a week in Summer 18, the list below shows the weekly flights and destinations from each UK airport to Poland
LPL - 27x flights per week to 9x destinations in Poland
BRS - 22x flights per week to 8x destinations
BHX - 21x flights per week to 9x destinations
EDI - 20x flights per week to 8x destinations
MAN - 20x flights per week to 7x destinations
DSA - 20x flights per week to 5x destinations
EMA - 16x flights per week to 5x destinations
BFS - 12x flights per week to 5x destinations
GLA - 12x flights per week to 5x destinations
LBA - 12x flights per week to 4x destinations
NCL - 8x flights per week to 4x destinations
BOH - 2x flights per week to 1x destination
PIK - 2x flights per week to 1x destination
ABZ - 2x flights per week to 1x destination