The rail union has agreed that services will continue as normal tomorrow - the original first day of the strike.

Transport for NSW is "scrambling" to bring in replacement transport amid the Sydney trains shutdown this weekend. But why are workers striking and exactly what is the union demanding?

Sydney's train network will grind to a halt from Friday to Sunday amid a pay dispute between the NSW government and the state branch of the Rail, Tram and Bus Union.

Andrew Constance said the abolition of NSW's public sector wage cap has been a 'disaster', and urged the train union to sit at the negotiating table.

NSW Minister for Transport Jo Haylen has said the industrial action on Sydney trains from Friday to Sunday would cause "major disruption for millions of train passengers" across the city.

The rail union has warned they won’t back down from industrial action which will strand millions of commuters this weekend — despite Premier Chris Minns stepping in to try and solve the issue.

Sydney is set to grind to a massive standstill as government-union negotiations fail to strike a deal over train driver pay.

Sydney trains will run on Thursday after a small concession from the rail union to delay strike action until Friday, amid an ongoing wage dispute with the government.

Sydney's train network faces a complete shutdown from Thursday night to Sunday morning as rail workers commence a strike. The Rail Tram and Bus Union (RTBU) initiated the industrial action following unsuccessful negotiations with the New South Wales government regarding pay and conditions.