The Government is today expected to announce a new Y-shape route for the controversial HS2 project from Birmingham to Manchester and Leeds.
Sources predict trains travelling partly on this new track could get from Glasgow to London in three hours and 38 minutes, down from the current four hours and eight minutes.
They also reckon HS2 would slash journey times from Glasgow to Birmingham from the current three hours and 57 minutes to three hours and 22 minutes.
The new rail project – expected to cost £32.7bn – is one of the Coalition's economic priorities, aiming to rebalance the UK economy with journey times of just 80 minutes between London and Manchester.
The project, however, will only be completed by 2033 with no timetable for extending the line to Scotland.
However, Deputy First Minister Nicola Sturgeon has talked of building a Glasgow-Edinburgh link high-speed link that would eventually be tied in to the English network.
Meanwhile, a legal challenge has been lodged to stop to force the government to reconsider its initial link between London and Birmingham because of concerns over the route.
Trains running on HS2 would be able to run on conventional track too – meaning passengers from Scotland would travel at conventional speeds to Manchester and then at up to 225mph onwards to London.
Economists are studying the impact of the network on business in Scotland and the north of England.
Railways expert Dr John Disney, of Nottingham Trent University, said: "This is the first major development of the railway system since Victorian times.
"The trains will bring the Midlands and northern economy closer to London and the south-eastern economic heartlands."