Seloco
I believe therefore that the time has come to make the very fundamental decision about LHR: either develop it properly into a 21st century airport, with all that that entails in terms of extra runways, terminals and infrastructure and demolition of homes and history, or close it down and build something decent somewhere else
Exactly why do we need to massively expand avaition in the UK? - It is an unfortunate fact of life that in the UK the main population and business is concentrated in the South East and that this area is rapidly approching saturation point.
In the US and to an extent mainland Europe there is not the pressure on available land, so these new mega-airports can be built without the impact on the lives of those living in the area.
If we do go to extra runways, terminals, railways, etc. etc. at LHR remember you will also need around 20,000 to 30,000 extra staff, as there is almost zero unemployment around LHR at the moment, where are they going to come from and live? (then you need extra schools, shops etc. etc.)
The UK is the 4th largest economy in the world - do we actually need the amount of transfer traffic through our congested airports? we could easily support a good-sized aviation industry with only the travellers to-from the UK.
I would suggest that rather than create all the associated problems with a new mega-airport we build extra runways at LGW and STN (that gives 3 two runway airports around London - not including LTN) and expand services from the other UK airports such as BHX, MAN, GLA etc. and try to spread the pain acroos the country. If this means that we get less transfer pax through London, so be it.