Rail bosses are to look at the possibility of building five new high-speed main lines as part of a review of the network's future, Network Rail said.
Network Rail said it was to commission a study which would look into the feasibility of new lines along the UK's busiest routes in what would amount to the largest track build since the 19th century.
The review, which will be announced on Monday, will also assess the need for high speed trains similar to the French TGV to cope with Britain's growing number of rail users.
Over the last decade, the network has seen passenger numbers increase by about 40%. More people are using the service than at any time since 1946.
Numbers are expected to swell by a further 30% in the next ten years, adding to the burden on the current network.
The study being commissioned by Network Rail will look at the service in the post-2014 period, with all options "on the table".
If given the go-ahead, the new lines are likely to run alongside some of the UK's busiest existing routes.
They include the West Coast line to Birmingham, Manchester and Glasgow, the East Coast line to Edinburgh, the Great Western to Bristol, the Midland main line to Sheffield and the Chiltern route to Birmingham.
The London to Penzance line will also be looked at as part of the review.
If the proposals are adopted, the new tracks are thought likely to be built with high-speed passenger trains in mind.
