Thanks for the replies. To repeat, MAN is just about unique amongst those European airports which are in or are about to enter the premier 25mppa+ range. All the others are one or all of the following:
1. A capital city airport, or principal city airport where the capital is not dominant.
2. Has benefitted from funding of core infrastructure by central government at some stage
3. Is the main base hub of the national flag carrier, or has a significant number of slots held by the national flag carrier.
MAN has none of the above characteristics and is therefore unique amongst this league of airports. Have a look at the list on the link below. The only other exception I can find is Palma Majorca (PMI) which has a similar volume to MAN but exists for one reason alone: massive inbound leisure travel, having a very small catchment of its own.
Edit: Actually I think PMI ticks item No. 2 in my list of characteristics and so MAN really is
unique.
https://en.wikipedia.org/wiki/List_o...orts_in_Europe