Hundreds of people have backed a petition against plans to terminate South London's Thameslink trains at Blackfriars Station.
The Department for Transport is consulting on the new seven year Thameslink franchise, with recommendations trains serving Merton on the Wimbledon loop should terminate early.
This would mean the borough will have to direct link to the City, St Pancras International and Luton Airport.
Campaigners, including councillors in Sutton, Lambeth and Merton submitted a petition to ministers on Thursday.
Merton Councillor Mary-Jane Jeanes said: "So many people have told us they've bought homes and put down roots in local communities based on the train services along the Wimbledon Loop.
"The proposals would cause further hardship and delay for passengers especially with considerable overcrowding at Blackfriars station if passengers have to change trains.
"Many residents living near to Thameslink stations do not have access to other services or the underground."
Anthony Fairclough, a campaigner, of Wimbledon Chase, said: "Local shop owners told us that Network Rail's proposals would also damage their business - many have employees or customers that come from beyond Blackfriars to Merton. Making it more difficult to get here isn't going to encourage them to come.
"We've been fighting these proposals since last year, and we won't be giving up just yet, the next stage of the campaign will begin after officials make their recommendations to ministers."
The Department for Transport has said the consultation will be extended until September 14.