The union has confirmed it is serving notice for strike action on Stagecoach buses in the South West, East Midlands and Derbyshire/Yorkshire as part of the national pay disagreement.
The union says it is looking at a 24 hour strike which would take place later this month.
RMT General Secretary Mick Lynch said: “The massive votes for action by Stagecoach members reflect the growing disgust amongst bus workers at being kicked in the teeth on pay while inflation and wages elsewhere are rising steeply.
“It's well established now that we are facing a national shortage of bus drivers as staff leave over poor pay and conditions. It is ridiculous that Stagecoach have chosen this moment to hammer their staff over pay. The consequences for local services will be horrific.
“RMT is fighting for professional wages for professional bus workers and our members are leading that charge right across the country now.
“We have had no option but to put this action on for the 18th October and the company should stop their attacks on their staff and start talking seriously about a just and fair settlement.”
The Stagecoach Yorkshire strike, affecting the company’s Chesterfield depot, is planned for Monday October 18, to run from 12.01am until 11.59pm.
There will also be a Stagecoach East Midlands strike the same day, running at the same time at the Mansfield and Worksop depots.
Stagecoach have said the RMT has continued to make unrealistic and unaffordable demands, and has urged workers to return to talks rather than striking.
A Stagecoach spokesperson said: "Workers and students who rely on buses to access jobs and education, as well as businesses struggling to recover from the pandemic, will be angry that the RMT is planning to disrupt their lives and livelihoods.
"We are committed to offering good packages for our people and, as well as protecting jobs during the pandemic, we have reached agreement on pay increases for many employees at a number of depots around the country."