Lambeth councillors joined forces last week to protest against planned cuts to the Wimbledon loop Thameslink service.
Councillors from the three main parties canvassed leaflets along the route before getting a train to Blackfriars where rail planners propose to terminate the trains from 2018.
The aim of the protest was to highlight a consultation being held by the Department for Transport in advance of the refranchising of Thameslink and Southern services later this year.
Councillor Lib Peck, Lambeth Council’s cabinet member for regeneration, said: "Lambeth has long campaigned for a better Thameslink Service and today's cross-party action shows how much support it has across the borough.
"We'll be sure to remind government that South London commuters must not be ignored".
Councillor Alex Davies, Liberal Democrat transport spokesman said: "Well over a thousand Streatham commuters took our leaflet this morning, and we're already getting responses piling in to our inboxes.
Local residents are rightly appalled that our only direct link through central London might be withdrawn.
We are urging the Department of Transport to listen to local passengers, not to the technocratic recommendations of Network Rail who seem to regard Streatham and the whole "Wimbledon Loop" area as little more than an inconvenience."
Streatham’s MP Chuka Umunna has appealed to the community to join him in the long-running to save local Thameslink services that run from Streatham and Tulse Hill.
He said: "I am appealing to as many members of the community as possible to respond to the government’s consultation on this issue.
"It is essential that we all act together to retain the links between Streatham, the City and North London.
"It is incredibly important for the convenience of everyone living here, as well as our local economy and the job prospects for local residents."
To show your support for the campaign you can email your objections to firstname.lastname@example.org or write to The Combined Franchise Replacement Sponsor, Department for Transport, Zone 3/15, Great Minster House, 33 Horseferry Road, SW1P 4DR.