Looking like Heathrow - Boris Johnson said he would lie down in front of the bulldozers to stop another runway being built - expect it up and running by Saturday with his full support then Lol !!
In a typical conclusion they were looking at either expanding Gatwick or a new 3rd runway at Heathrow. Seems the option chosen is extending runway 1 at Heathrow . That wasn't even part of the bid/plan !!! It was a 3rd alternate suggestion submitted by a private contractor - we are so shit at travel infrastructure planning and delivery