Transport for London (TfL) is seeking a contractor as it plans to build an extension to the London Overground line to serve the new Barking Riverside development.
The current Fenchurch Street to Tilbury line runs to the north of the site, between Barking and Dagenham Dock stations, but the new spur would turn south between these two stations and run for 1.5 km to the new Barking Riverside terminus station.
In addition to this new stretch, a 3 km stretch between Barking Station and the start of the spur will be upgraded.
Already fully funded, work on the £263 million project is set to start next year and be completed in 2021.
London's deputy mayor for transport Val Shawcross commented: "The extension of the Overground will be key to the success of the exciting new developments at Barking Riverside."
The 443-acre development will see around 600 homes being built each year in four phases of development.
