Sydney commuters in limbo as commission mulls quashing rail union's industrial action

Sydney commuters remain in limbo as the NSW government awaits a decision by the Fairwork Commission on whether to halt industrial action, alleging the Rail Train and Bus Union (RTBU) organised a mass sick day.

Sydney Trains has warned that lengthy delays and service gaps are continuing today due to a "high level of staff absences from industrial action".

Commuters are advised to plan ahead and allow extra travel time due to delays and 16 cancellations.

READ MORE: Police try to determine charges after Sydney nurse's home searched

It comes after a rail network meltdown yesterday saw more than 1000 services cancelled.

Sydney Trains and the RTBU arrived at the Fairwork Commission today, where the state government is applying to pause the industrial action.

"We're here today to seek to prevent this industrial action that's really causing such a difficult time for passengers," Sydney Trains chief executive Matt Longland said.

Outside the Commission, RBTU branch secretary Toby Warnes said there was "no chance" the dispute would be resolved today.

The government is alleging the union coordinated a mass sick day yesterday after 570 rostered workers called in sick - a 28 per cent increase compared to the last six Fridays.

It was the most number of staff to call in sick than on any day during the COVID-19 pandemic.

READ MORE: Teen girl dragged in front of family, assaulted by group as old as 33

The allegation followed a text message that was sent to a number of members from union convener Adam Doyle that read: "let's f--- the network up."

The union refuted that allegation.

"I mean, I'd love to take credit for a sophisticated covert campaign but we didn't organise any sick-out yesterday," Warnes said.

"I've never spoken to Adam Doyle. I do not know who he is," he added.

But Doyle does exist and Warnes said he will speak to him as the union is worried about his welfare following the backlash he received over yesterday's incident.

READ MORE: Camper hospitalised for Japanese encephalitis, renewing warnings from NSW Health

A decision on whether the industrial action is paused will be handed down tomorrow by Fairwork Commission's Deputy President Thomas Roberts.

If the industrial action continues over the weekend, it will most likely impact concertgoers heading to Sydney Olympic Park for Drake's opening night at Qudos Bank Arena on Sunday night.

Regardless of tomorrow's outcome, Sydney Trains is preparing for a chaotic commute on Monday.

"We will provide advice when we draw the plans up for Monday but certainly remind people whilst this industrial action is in place, they should expect to see impacts across the rail network," Longland said.

DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play