The new 3.2km runway would require a diverting the M25, building a new road tunnel under the airport and widening the motorway between junctions 14-15. Thomas Woldbye, the CEO at Heathrow said that the new M25, 100m west of the current one, would be ‘wider and it will be safer and it will have more capacity’.

Bosses at Heathrow say growing the airport will boost the economy, but they face opposition from campaigners and the Mayor of London

London's Heathrow Airport on Friday unveiled a £49-billion ($65 billion) expansion plan, including the costs of building a long-awaited third runway, approved by the UK government after years of legal wrangling.