Land required for extension beyond Abbey Wood terminus to be safeguarded from any alternative use

Crossrail's route could be extended further east with an additional line between Abbey Wood in south London and Gravesend in Kent.

Plans for the £16bn trans-London line include an offshoot that terminates at Abbey Wood, and no commitment has been made to extend beyond this point.

However, the Department for Transport (DfT) announced today that it would leave the door open to an extension of the offshoot by preventing development around the area where it would be built.

Transport minister Sadiq Khan said safeguarding the area would “allow this important rail project to be extended in the future if the business case stands up. By doing this we are future-proofing Crossrail.”

He added: “The government is committed to Crossrail and the economic benefits it will bring to London and the South-east.”

Preparatory works for Crossrail will continue throughout 2009, and next year main construction will begin of the 118km track running from Maidenhead and Heathrow in the west to Shenfield and Abbey Wood in the east.

The high-speed network is due to open in 2017 and will increase London's rail capacity by 10%. It aims to substantially cut train journeys across the city, bringing an additional 1.5 million people within a 60-minute commuting distance of the UK capital's business districts.

It is hoped the project will employ 14,000 people at its peak, and support 7,000 further jobs linked to the project.