M25 could be rerouted under new Heathrow runway if plans get green light

The latest plans for a third runway at Heathrow Airport suggest rerouting the M25 through a tunnel.

This, the airport says, would involve lowering the country’s busiest motorway by seven metres between junctions 14 and 15.

Plans also include repositioning the motorway 150m to the west.

Changes to local roads and motorway junctions are suggested as well, with MPs expected to vote on the plans – first proposed in 2003 – later this year.

The airport says the total cost of the expansion scheme will be around £14bn – some £2.8bn less than originally suggested.

Work would begin in 2021, with the runway taking its first flights in 2025. The new plans would, for the most part, allow the M25 to stay open as the new section was built, reducing congestion, airport officials said.

Previous reports had suggested the runway would form a bridge over the motorway.

Now the airport wants to hear views from the public.

Emma Gilthorpe, Heathrow’s executive director for expansion, said: “We want an expanded Heathrow to be the world’s best airport, ensuring that our country and its future generations have the infrastructure they need to thrive.

“We need feedback to help deliver this opportunity responsibly and to create a long-term legacy both at a local and national level. Heathrow is consulting to ensure that we deliver benefits for our passengers, businesses across the country but also, importantly, for those neighbours closest to us.”

Over the past year, Heathrow has been working alongside local stakeholders and airline partners to evolve the plans it submitted to the Airports Commission.

If the scheme is approved, Heathrow will submit a planning application after consulting local communities.