There is overwhelming support for the Crossrail 2 high-capacity rail line between south-west and north-east London, according to the findings of a public consultation by Transport for London (TfL) and Network Rail.
A majority (95%) of almost 14,000 respondents strongly supported or supported the principle.
As part of the consultation, respondents were asked to express views for both regional and metro options. About 84% of respondents strongly supported or supported a regional option, while 73% of respondents strongly supported or supported a metro option.
Mayor of London Boris Johnson said: "This consultation reveals that there’s a very clear stamp of approval for Crossrail 2 from Londoners and from business."
"People can clearly see the immense value of a project that will relieve pressure on suburban rail routes and on the Underground, as well as helping to spur economic growth in a key quadrant of the capital."
Crossrail 2 would help to relieve congestion on busy main line routes into central London and on the Underground network.
The regional option could benefit people in London, Hertfordshire, Surrey and beyond, while the metro option could offer a high-frequency underground service across central London.
According to TfL, a metro option could operate between Wimbledon and Alexandra Palace.
TfL planning managing director Michele Dix said: "Crossrail 2 is vital if we are to support the predicted 10 million people that are expected to be living in London by 2031.
"The positive response we have received from the public and stakeholders for Crossrail 2 is really encouraging, it could be operational in 2030 but it is essential that work continues now to meet this target."