Confused commuters face a once-in-a-generation weekend shutdown of Australia's largest urban rail network if a last-ditch meeting fails to avert the crisis.
Trains from Newcastle to Wollongong and across Sydney are due to lay dormant from Friday morning until Sunday night amid an escalating pay dispute between the NSW government and rail workers.
The Labor government warned of a four-day stoppage, but that was reduced to three days on Wednesday, which the state branch of the Rail, Tram and Bus Union said was due to train officials misreading its plans.
Premier Chris Minns told parliament he would meet with the union on Wednesday afternoon in an attempt to break the impasse.
The union's secretary Toby Warnes said the shutdown could be avoided if the government met its demand of 24-hour rail operations.
"All it would take is a couple of extra services between 1am and 4am in the morning," he told reporters.
"This is a clear choice by the government to shut the network down."
Transport Minister Jo Haylen said the onus was on the union to drop its work bans after a proposal to run one line for 24 hours failed to halt industrial action.
"The government will keep its options open, but right now our focus is to bring this together, not to take court action and to drive it apart," she said.
"My number-one priority is minimising disruption to passengers and keeping the network moving."
That's proving a challenge under the weight of other union work bans limiting kilometres driven and signal operations.
Services were run around the clock over the previous weekend to ward off stop-work bans.
The train network moves more than one million people on a typical day.
The stand-off has resulted in commuters being asked to arrange to work from home on Friday. (Flavio Brancaleone/AAP PHOTOS)
Opposition Leader Mark Speakman said "industrial terrorism", ministerial incompetence and government cowardice were to blame.
"This is a minister who is out of her depth ... who leaves the public confused as to whether this is a lockdown by the state or a strike by the workers," he said.
More than 100 trains were cancelled on Tuesday evening, with stoppages along intercity lines and reworking of shift duties.
But Mr Warnes said the numbers shouldn't be taken seriously and there was a tendency to blame industrial action for every problem on the rail network.
The union wants four annual pay rises of eight per cent and a 35-hour work week, while the government has not budged since June from its offer of 11 per cent over three years.
The continuing stand-off has resulted in workers being asked to arrange to work from home on Friday to ease the strain on bus replacements.
"We will do everything we can, but we cannot accommodate a million people a day switching to other modes," transport secretary Josh Murray said.
Business Sydney director Paul Nicolaou said 24-hour trains would benefit the city, but they should not be used as a union bargaining tactic.
The Sydney Metro from Chatswood in the north to Sydenham in the inner west will also close for maintenance, with Transport for NSW advising commuters to "use train services".