Plans to turn single track rail lines into double tracks through Worcestershire, Gloucestershire and Oxfordshire are being considered.
Network Rail said it is looking at options to improve performance on the Cotswold Line.
A spokesman added that any work would probably not start before 2009.
Mid Worcestershire MP Peter Luff has appealed to passengers to put pressure on the company "to redouble as much of the line as possible".
Mr Luff, who has campaigned on the issue, said Rail Minister Tom Harris has told him that the industry will now be consulted on the details of the idea.
The Mid Worcestershire MP said: "There have been hints and expressions of hope, but this is the first time I have had it in writing from a government minister that redoubling will take place.
"I could not be more pleased. What a brilliant start to 2007!"
Network Rail said plans were at the "very early stages".
The company said it is mostly a single-track route between Worcester and Oxford and it is assessing the cost and implications of improving the line.