A third runway could allow airport to expand to 150 million passengers a year, nearly double the current scale

Heathrow says expansion is "urgent" for UK growth, but plans are heavily criticised over environmental concerns.

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’.