Rail commuters from Brighton, Hove and Portslade may be given a second mainline route to London.
Transport Secretary Patrick McLoughlin has asked Network Rail to look at ways of increasing capacity between London and the south coast.
Specifically, he wants to know whether reopening the Uckfield to Lewes line “will meet the demand for the future growth in rail travel”.
The Conservative Transport Secretary discussed the issue with the Liberal Democrat Lewes MP and fellow coalition transport minister Norman Baker during a trip to Lewes yesterday.
The two men visited Lewes Railway Station which lost its link to Uckfield more than 40 years ago when it was closed by East Sussex County Council.
Mr McLoughlin said: “I am alive to local interest in reopening this line and wider concerns about rail capacity between London and the south coast and this is why I have commissioned this study.
“It will help us to understand exactly what the issues are and build upon previous work that has looked at these questions.”
Mr Baker has long supported reconnecting Lewes and Uckfield but opposes the Brighton Main Line 2 (BML2) project which aims to revive direct trains between Brighton and London along the route.
Lord Bassam, the former Labour leader of Brighton and Hove Council, backs as do the the three Brighton and Hove MPs and many councillors.
Brian Hart, who instigated the Wealden Line Campaign 27 years ago and is BML2’s project manager, said that Network Rail had nowhere else to go to increase capacity.
He said that the Brighton main line was full and could not be expanded.
But yet another Lewes to Uckfield study would meet the same fate as all the others over the past 40 years, he warned.
Mr Hart said: “Network Rail’s 2008 study proved beyond doubt there was neither a business case nor an answer to their capacity conundrum by opening a local line.”
He said that the root of the problem was the absence of an additional direct Brighton to London main line.
It could be addressed only with BML2’s proposed Ashcombe tunnel through the South Downs. He said: “Tunnel construction is easy and has been revolutionised as Crossrail is demonstrating. It’s akin to pushing an apple corer through cheese.”
The Department for Transport said: “Recent moves to devolve decision-making for local transport schemes will also give greater freedom to local councils and enterprise partnerships to determine priorities and allocate funding accordingly.”
Mr Hart added: “While we are all heartened that Patrick McLoughlin is ‘alive’ to opening the line, this is not a local issue but a massive problem for London and the South East.
“It can’t be done on a shoestring. Without BML2 the region will ultimately reach rail gridlock as this is the only realistic means of providing the capacity so badly needed.”