The south eastern branch of the Elizabeth line will not be open until at least October next year, it has been revealed.

Crossrail staff have identified a six month window for trains to begin operating along the section between Abbey Wood and Paddington.

Intended to open between October 2020 and March 2021, it will initially operate with 12 trains per hour. The Elizabeth line was originally due to be fully operational in December last year.

It is expected that all stations on the route, including Canary Wharf and Custom House, will be open except for Bond Street, which will not be ready until 2021.

A Crossrail spokesman explained: "The remaining systems installation in the stations and tunnels will be completed this year.

"This will allow the new stations and rail infrastructure to be integrated with the rest of the railway.

"During 2020 we will undertake testing of the completed railway including an extensive period of trial running and trial operations to build absolute confidence in the safety and reliability of the whole system before opening to the public."

Once the Paddington to Abbey Wood section - known as the central section - opens, phased services will be introduced across the entire Elizabeth line route. No date has been given for this to happen.

The two other branches are already in operation under the TfL Rail banner- Liverpool Street to Shenfield in the east, and Paddington to Heathrow in the west.

Some of the new-look Elizabeth line trains have already been introduced on these routes, with a 70-strong fleet of 200m long trains set to serve the Elizabeth line when complete.

Mark Wild, chief executive of Crossrail Ltd, said: "I share the frustration of Londoners that the huge benefits of the Elizabeth line are not yet with us.

"Crossrail is an immensely complex project and there will be challenges ahead particularly with the testing of the train and signalling systems but the Elizabeth line is going to be incredible for London and really will be worth the wait."

Around 200 million passenges are expected to travel on the Elizabeth line every year.

Ten new stations have been built while existing stations have received upgrades including more spacious ticket halls and step-free access to the platforms.