Heathrow Airport has updated its controversial expansion plans to build a third runway and increase the number of flights to more than 750,000 a year – and is asking the public for feedback.

Plans to expand the west London airport have existed since the 1940s, but it was not until 2003 that they began to receive government backing.

That support was withdrawn in 2010, with alternative proposals for new airports across London emerging before Heathrow's expansion returned to favour in 2018 as part of a revised national strategy.

Heathrow shown with a third runway over the M25
Heathrow shown with a third runway over the M25 (Heathrow)

Court battles followed, but by 2019 the plans most people recognise today, including a new runway to the northwest of the airport, had begun to take shape.

Heathrow currently handles about 470,000 flights a year. It wants to increase this to around 750,000 flights annually to accommodate growing passenger demand.

Supporters say the airport, which is operating at capacity, needs a new runway to meet growing demand for aviation or risk missing out on opportunities for businesses, passengers and communities.

Opponents argue that the economic benefits, particularly for communities closest to the airport, are vastly overstated and that the environmental damage would be too great.

Now, following years of technical and environmental work, Heathrow has revised its proposals and launched another public consultation, running from October 27 to December 22.

Residents, businesses, passengers and other stakeholders are being invited to have their say on the updated plans.

Among the most significant proposals is the construction of a new section of the M25, which would pass through a tunnel beneath the runway, along with the rerouting of the A4.

Rivers would also be diverted to make way for the new runway and taxiways.

The proposals are likely to reignite debate among nearby communities.

Heathrow also hopes to build a new terminal west of Terminal 5 and create an upgraded western terminal area between Terminal 5A and T5XW.

Future rail connections from the west and south would be incorporated into the designs, with space reserved for a station should the proposals eventually receive approval.

Key Surrey consultation dates

November 9, 6.30pm: Online overview of the updated expansion proposals.

November 12, 2pm to 7pm: Stanwell Moor Village Hall. An opportunity to learn about the expansion proposals and speak to Heathrow's team.

November 16, 6.30pm: Online session covering proposed road and surface access changes.

November 17, 1pm to 7pm: Walton Exl Sports Hub, Walton-on-Thames.

November 19, noon: Online session explaining how aircraft noise is assessed, how it could change and measures proposed to manage it.

November 21, 10am to 3pm: Egham Hub.

November 23, 6.30pm: Online session explaining how the phased construction programme would be delivered.

December 3, noon: Online session examining how the effects of expansion would be assessed, avoided, reduced and managed.

December 5, 10am to 5pm: Staines Community Centre.

December 10, noon: Online overview of the updated expansion proposals.

December 12, 10am to 3pm: Stanwell Village Hall.

Further information about the consultation is available on Heathrow Airport's website.