The Passenger Rail Agency of South Africa said in a statement on Thursday that its commuter rail operator Metrorail would provide limited commuter service on the day of a national strike due to take place on Friday.
The Prasa statement said this was because critical safety staff that the commuter service depends on would also likely be participating in the industrial action.
Train drivers will embark on the mass action to demand better working conditions, including enhanced security and the implementation of railway safety guidelines.
The strike by the United National Transport Union is expected to affect Metrorail operations around the country.
The Prasa statement said while it intended to keep the commuter rail service going on Friday, services would not be at an optimal level because safety staff were expected to participate in the industrial action as well.
"Because the majority of safety critical staff may be participating in this mass action, Metrorail will operate a reduced service, similar to that offered on Saturdays and Sundays," the statement said.
The Prasa statement said because the industrial action was "not a labour strike against Prasa but a Federation of Union South Africa-led mass action against government", not all Prasa employees within operations would be participating.
The statement, however, recognised UNTU's right to demonstrate, as a Fedusa affiliate. Prasa advised passengers to expect longer waiting times than usual due to the expected limited service on Friday.
An UNTU statement released earlier on Thursday said the union's general secretary Steve Harris wrote to acting group CEO at Prasa, Nkosinathi Sishi, asking for the proof that employees have been declared an essential service in terms of section 213 of the Labour Relations Act.
Harris said information at the union's disposal suggested no provisions were made to include Prasa employees among those deemed to be essential services.