Plans for a multibillion-pound north-south rail line with 250mph trains will be presented to the Government either today or tomorrow.
Contained in a report from a company set up by the Government, the plans will include a detailed route - exact to within 18 inches - of a brand-new line from central London to the West Midlands.
Operating from a huge, new station in central London, the 400-metre-long trains would carry 1,100 passengers in a project which could cost as much as £60 billion.
The station would be big enough to handle 14, and eventually 18 trains an hour, with 20,000 passengers travelling in and out every 60 minutes.
The report, from the High Speed Two (HS2) company, will also present options for a high-speed line, or lines, north of Birmingham up to Scotland.
If accepted by the Government, the first part of the line - from London to the West Midlands - could be up and running by 2025, with work starting on it in 2017.
Running to around 200 pages but with thousands of pages of appendices, the report will not be published until spring 2010.
If the Government decides to pursue proposals for high-speed rail, it will publish a White Paper by the end of March 2010.
HS2 was established to identify a buildable route, with station options, for a high-speed train service from London to the West Midlands.
HS2 will present options for possible connections to Heathrow airport and to the Channel Tunnel rail link, now known as High Speed 1 (HS1).
The HS2 team looked at 35 possible sites in London for the high-speed terminus and have settled for a site right in the centre of the capital.
Ministers will be presented with a minutely-detailed route for the line as far north as the West Midlands.
This will be a new line which will hug the contours of the land, with noise and visual impact being reduced as much as possible.
However, the line is almost certainly set to go through the Chiltern Hills in Buckinghamshire - a beauty area where there is likely to be much opposition to the project.
HS2, which sees the high-speed trains as “aeroplanes on wheels”, will also present a range of costs for the line. The company will be less specific about the route and costs of extending the line beyond the West Midlands.
The London to West Midlands route will contain some tunnels - something which always adds considerably to the cost of a road or rail project.
HS2 chief executive Alison Munro said: “We were asked to look at linking with (the cross-London rail scheme) Crossrail, the Great Western main line and with Heathrow.
“The report will set out a case for various options including a possible link with HS1. The proposals will include running trains from the HS2 on to the West Coast Main Line.
“This will not be a transport project in isolation. The final report will look at how the line will help housing and regional economic development. There will be significant levels of detail.”
The HS2 team realises that there will be much demand from each region to be included on the high-speed route.
But Ms Munro said: “You don’t want to stop your high-speed trains at numerous stations along the way.”
HS2 will present the facts in an impartial way. HS2 chief engineer Andrew McNaughton said: “We are not here to promote high-speed rail. We are not cheer leaders. We are evaluators.”
The Government’s White Paper - should there be one - will set out detailed plans for new high-speed rail lines and services, including route proposals, timescales and associated financial, economic and environmental assessments.
This would be followed by a full public consultation, starting next autumn, giving all interested parties an opportunity to comment before the proposals are finalised.