It makes no sense to expand (or try to expand) Heathrow. There is no room and moving the M25 is just another idiotic idea from the people who are allegedly running this country. MP's are clueless and come up with these ideas just to keep themselves in jobs.
Stansted is by far the most sensible airport to expand as it already has most of the infrastructure in place, has room for expansion and would cost the tax payer much less money and disruption.
Mind you, nobody will listen to anything anyone says as it does not suit the MP's !