Industrial action will take place in all federal states except Bavaria on Friday Feb. 2, Verdi deputy chairwoman, Christine Behle, said in Berlin.
"The time has come to put more pressure on the employers," she added, referring to failed wage negotiations in all federal states.
Around 90,000 employees from more than 130 municipal companies are affected, she said.
Central to the negotiations is the improvement of the employees' working conditions, a Verdi statement said, listing reduced weekly working hours and increased holiday entitlement as demands.
"We have a dramatic shortage of labour in public transport and incredible pressure on employees. Busses and trains are cancelled every day in all fare zones because there are not enough staff," Behle said.
(Reporting by Klaus Lauer, Writing by Nette Nöstlinger, Editing by Thomas Escritt)
