Protests are being planned along the route for a bus service that will be discontinued in six weeks.
Campaigners claim that the Dumfries-to-Edinburgh service is a "vital connection" for the communities it serves.
To protest the removal of their route, they plan to hold a demonstration at several stops.
The councils that funded the service are currently in talks and have indicated their commitment to finding a solution.
The 101/102 service connects south west Scotland to the capital and serves many towns and villages, including West Linton and Biggar.
The current Stagecoach West Scotland contract expires on the 13th of August.
The reason why a new deal was not awarded is due to a sharp increase in the costs of running the service.
A petition online has attracted thousands of signatures, and now there is a planned demonstration.
"This has just landed in communities in the past few days," stated Ian Reid, a West Linton resident.
"It has become apparent that the bus service is in serious danger of being withdrawn within six weeks."
"There has not been any formal notification or community consultation."
A weekend-long online meeting was held to discuss the impact of the disaster.
Barry Knock, chair of Quothquan and Thankerton Community Council said that the impact on rural communities' viability would be substantial.
He stated that there was "a lot" of anger over the "loss to this vital link."
Dumfries and Galloway Council, one of the affected local authorities, released a statement saying it understood and shared the concerns.
It stated that it was working with Swestrans, the local transportation partnership it funds, in order to find a solution.
In the statement, it was stated that 86% of the cost for procurement had been proposed. This was unacceptable.
Co-leaders Linda Dorward, and Stephen Thomson stated that they are in discussions with all funding partners as well as the local authorities of Midlothian and Edinburgh to find a solution.
Stagecoach, the current operators, stated that the financial climate and travel patterns are "completely different" than when the service was offered in 2018.
It stated that Covid's impact on passenger numbers, high inflation, and rising fuel prices all had increased the underlying costs.
The local authority stated that the operating costs of its previous contract were not sufficient to cover them and that it could not sustain such financial strain.
It said that it is happy to partner with local councils in order to provide sustainable bus services.