East Coast Main Line and London Midland cleaners are set to strike for 24 hours next Monday following a 98 percent vote for the action.
Both sets of workers are employed by ISS. The company has refused to offer them a pay rise for three years.
With increased inflation, this means they have suffered a pay cut. They are demanding a living wage.
Cleaners on London Midland have struck previously—but this is the first time workers on different lines will be striking together in the dispute.