The earth and stone piling up near Royal Oak tube station, Paddington as Crossrail bore their tunnels, may not look like a vision of awe inspiring natural beauty.

But that is what it could become, as crossrail bosses announced plans to use the earth dug from beneath Westminster to build the biggest man-made nature reserve ever.

Excavated waste from all the project’s tunnels will be sent to Wallasea Island in the Thames Estuary to build a wetland twice the size of the City of London.

The excavated earth will be loaded onto frieght trains before being sent Northfleet in Kent to construct the home for birds endangered by rising sea levels.

Crossrail chief executive Andrew Wolstenholme said: “This landmark project is a pioneering example of how the construction industry and environment groups can work in partnership to build a sustainable Britain that benefits both the economy and the environment.”