Another fix :
1. All long haul traffic to go from Heathrow
2. All short haul including Europe etc to go from Gatwick, Luton etc.
Uhh - how does this work, exactly? My last return trip, as SLF, involved BA LFPG-EGLL (short) and BA EGLL-KDEN (long).
As it was, we barely caught the second flight - even with a 1.5-hour layover - in the same terminal.
Are you really proposing that we'd have had to fly to Gatwick, exit the secure area,
cross London, repass security - just to fly two legs with the same carrier? How many hours would
that take?
________
Anyway, as a Yank, far be it from me to offer advice. Just some observations.
Denver got a big, new, greenfields airport 20+ years ago. Mostly because it was the Mayor's own baby (Federico Peņa, later US SecTrans), and he had the political clout and connections at all levels of government (local, state, federal), and was willing to cash them in, to get it done.
About like Ancient Geek's proposal - 6 runways.
(We are only now (well, Spring 2016) getting the rail connection, after 20+ years - but we know the US is a desert as regards passenger rail).
But-
1. We literally had green fields (well, yellow) - 300-500 miles of nothing but wheat farms between us and the next big city (depending on how you define "big" - Topeka or Kansas City).
Which was good, because given the requirements for long runways (5,280-foot-elevation plus summer temps nudging 38°C makes for - interesting - density altitudes); and wide spacing (specs called for the capability to handle 3 simultaneous ILS approaches), the present KDEN would more or less fill the whole area between BHX and the outskirts of Coventry (53 square miles).
The first doesn't apply to London - the second might.
2. There was a reasonable positive economic argument in favor of the new airport. Not just more traffic
to Denver, but as a hub, more jobs as United and Continental (as was) moved more people
through Denver.
Seems like, for London, expanded airport capacity is more a question of keeping up than jumping ahead (which I mean as a compliment - London is already and will always be a world-class City, with or without new airport capacity - Denver needed the help.)
I don't see that there is a better solution, given that the UK is full right up with people, hedgehogs, castles and chalk men, than expanding Heathrow. Someone's ox gets gored, in any case.
And (back to the thread title) it will take someone to be a political sugardaddy and make it his or her mission to push that through, expending political capital as needed.