The decision to turn off Opal machines was made to highlight the "impending franchising" of buses in the inner west region,’ the Sydney Morning Herald reports.
"This 'Fare Free Day' is about telling commuters that Andrew Constance is selling their local buses without their consent or approval" Rail, Tram and Bus union, bus division president David Woollams said in a statement on Thursday.
"The 'expressions of interest' period for private bus operators has been brought forward and closes today 1 June, after only being open for just one week," he said.
The fare-free day will run across 12 Sydney depots currently managed by the government-owned State Transit, including the inner west, eastern suburbs, north-west suburbs to Epping, and across the lower north shore and to the Northern Beaches.