The gates to the city’s rail network have been thrown open, as union members begin a planned three-week period of industrial action and Sydney Trains management urges customers to pay regardless.

Beginning at 6am on Saturday, station staff who are members of the Rail Tram and Bus Union said they would leave the gates open at all stations across the network, meaning those using the train system did not have to tap on and off to access it.

While passengers could run the risk of a fine or caution if they do not tap on and off, the union has banned its members from issuing fines or cautions until September 6 as well.

The industrial action is planned for a three-week period, which Sydney Trains management warned could cost the state up to $10 million in lost revenue.

“Tapping on and tapping off ensures commuters are charged the correct fare, and can access Opal benefits, including daily and weekly travel caps,” chief executive Matt Longland said.

The RTBU and the state government are at loggerheads over NSW’s new intercity train fleet, which the union says is unsafe.

Two ministers met with union leaders on Thursday night and agreed to provide a deed next week guaranteeing the government would make modifications to the trains.

The union vowed to continue with industrial action until it receives a deed satisfying the demands of its members for safety modifications to the guards’ compartments.

Unless a deal can be struck, commuters are likely to face major disruptions on the T8 Airport and South, T3 Bankstown and Southern Highlands lines next Wednesday with another six-hour work stoppage planned.

With Matt O’Sullivan