“Crossrail is not just a transport scheme – it is the key to the next 20 years of economic development of London," he said.

“Crossrail will provide the transport underpinning for the greatest centres of London’s business – the City, Canary Wharf and the West End – as well as linking these areas of high jobs growth to the areas of greatest deprivation in east London and opening up the areas of new housing development in the Thames Gateway.

With a capacity twice that of the Jubilee line, and expanding London’s rail capacity by 10 per cent, Crossrail is the largest addition to London’s transport system for more than fifty years. It is expected to cost around £16 billion.