Government cash approved for bid to double capacity of West Norfolk's trains
Work to double the length of trains running to and from Lynn is set to start later this year after government funding for the scheme was approved.
Officials say it is likely to be late next year before passengers will see regular eight-coach trains running between Lynn and Cambridge, instead of the current four.
But political and business leaders have welcomed the move, which follows recent talks between them and industry bosses.
South West Norfolk MP Elizabeth Truss said: "I am delighted that funding has now been agreed.
"This is extremely positive and will be welcomed by the many rail users who have become increasingly frustrated by the overcrowding on the Fen Line.
"More and more travellers are using this train route and I will continue to ensure delivery remains on time and Network Rail keeps to its timetable of works."
Discover King's Lynn chairman Darren Taylor added: "The town centre business community welcome this news. It’s been a slow process but I think it’s clear that we are making progress.
"I would urge the rail authorities to redouble their efforts to get this work done as soon as practically possible.
"We are still pushing for half hourly trains and the King’s Lynn Town Centre Partnership will continue to do all we can to ensure this is delivered as soon as possible.
A letter from Network Rail officials to Ms Truss said the project would include additional storage space at Lynn, plus platform extensions at the Littleport and Waterbeach stations.
The document suggested work would begin this autumn and be completed by the summer of next year, with the first eight-coach trains expected to run in December 2020.
Matt Brennan, Network Rail's public relations manager for the Anglia region, wrote: "Everyone at Network Rail appreciates the desire amongst residents, local representatives and our partners at Great Northern to see this scheme delivered.
"We know that existing four car peak trains on this line are overcrowded just now, and that extending trains would add much-needed capacity."