The project, which was approved in 2007, will deliver a new London Underground-like railway, crossing East-West through central London, called the Elizabeth Line. The line runs from Reading through central London, from Paddington to Liverpool Street, before branching off to terminate at Abbey Wood in southeast London and Shenfield in Essex. Construction began in 2007. The Elizabeth Line was originally scheduled to open in 2018.

More than three years behind schedule, the central section of the railway – between Paddington and Abbey Wood – is finally approaching a mooted opening date in the first half of 2022. The project was handed over to TfL in October 2020.

The final stage of the project involves 'dress rehearsal'-style trial operations to ensure safety and reliability of the railway for public use and to test the feasibility of the timetables.

TfL Commissioner Andy Byford said: “Everyone is working hard to make sure we can open the Elizabeth...