Any further disruptions on the nation's busiest rail network should be put down to operator incompetence not industrial action, a union says after drawn-out pay talks ended with a dramatic legal intervention.
The NSW government took the state's Rail, Tram and Bus Union to court a day before work bans were due to resume on Monday, a move that came too early for the union but too late for the state's opposition.
Passengers were told to plan ahead in the morning as reduced services operated and some trains were replaced by buses.
Premier Chris Minns said train drivers could not get a pay rise while nurses were denied one.
An agreement was "a whisker" away, according to the union, but parties were "too far apart" for the premier after a two-week truce for intensive bargaining.
"We worked incredibly hard ... but we weren't able to pull it off," Mr Minns said.
"We don't have a blank cheque to hand over."
Another Federal Court hearing is expected to decide the fate of future industrial action, while separate dispute hearings take place in the Fair Work Commission.
Resuming industrial action required a vote by members and was unlikely before Christmas, union secretary Toby Warnes said.
Members had intended to limit the distances they operated trains and progressively reduce the number of kilometres each day until a deal was done, but the injunction did not totally avoid disruption to services.
Transport Minister Jo Haylen said more than 70 per cent of suburban trains ran on time on Monday morning, but intercity services were significantly impacted.
"We need certainty for passengers and for our rail network, and we'll continue to work towards an agreement while keeping our city moving," she said.
But Mr Warnes said any further disruptions were attributable to the "gross incompetence of Sydney Trains to actually run the network" as the industrial action had been called off.
The "vicious" legal actions during formerly co-operative discussions caused an attitudinal shift that made continuing negotiations a lot more difficult and would delay an agreement by months, he added.
"We had our issues with the last government, but we know we never saw anything as bad as what we saw over the weekend," he said.
The union is calling for annual pay rises of eight per cent for four years, while the government says anything more than 11 per cent across three years is unaffordable.
A temporary truce was struck in November after commuters faced the prospect of a weekend-long rail shutdown, but the government did not shift its position on pay in the face of similar demands from key frontline workers.
Opposition transport spokeswoman Natalie Ward said the government should have gone to court much earlier.
"They've had months to sort this out," she told reporters.