Sydney trains could stop for four days if no compromise

Late-night meetings could potentially avert four days of chaos on the transport system in Australia's most populous state.

A months-long dispute between the NSW government and the state branch of the Rail, Tram and Bus Union (RTBU) escalated on Tuesday when Transport Minister Jo Haylen announced no train services would run for four days.

"As a result of the union not withdrawing their bans, I need to inform the travelling public that there will not be train services between Thursday and Sunday this week," Ms Haylen told reporters.

The rail union has been increasing work bans and threatening to strike if 24-hour services weren't available on those four days.

Union secretary Toby Warnes said the announced shutdown period would begin before the union's advised action.

The four-day shutdown was the government's decision, he added, but the union was prepared to take some blame.

"Yes, the public may hold us responsible for the shutdown, but they should only hold us responsible for the shutdown on the Friday and the Saturday night, and only to the extent that they understand or that they believe that the government can't actually run 24-hour services," he told reporters.

While Ms Haylen and Mr Warnes spoke to reporters on Tuesday afternoon, there was hope they could talk to each other and avert chaos on the public network.

"There hopefully will be an in-person discussion today, and my hope is that we don't see a shutdown of the rail network," Sydney Trains chief executive Matt Longland said.

Mr Warnes said he spoke to Mr Longland about that on Tuesday afternoon.

"I said we're making ourselves available all night tonight ... we're available at all hours of the day to ensure that we can get this sorted," he said.

Ms Haylen said her door was open and her phone was on.

"I am willing and able to meet with the union at any time," she said.

The union offered to meet on Tuesday morning to discuss critical maintenance going ahead while running services 24 hours a day, Mr Warnes said.

The 15-minute web conference with an operational manager involved a briefing about a proposed 24-hour service on only one line, which was not enough to avert planned action, he said.

Ms Haylen said the onus was on the union to drop its work bans after it knocked back the proposal.

More than one million people use Sydney trains on a typical day, while the ban is also expected to affect inter-city services.

Extra bus and other services will be rolled out, but the shutdown will strain the capacity of replacement transport.

The shutdown is expected to impact two Pearl Jam concerts at Sydney Olympic Park and an A-League match at Moore Park.

The pay stand-off comes after services were run around the clock over the previous weekend to ward off stop-work bans.

Transport officials said continuing services around the clock from Thursday to Sunday was not sustainable.

The Sydney Metro from Chatswood in the north to Sydenham in the inner west is also closed for maintenance on the weekend, with Transport for NSW advising commuters to "use train services".