Sydney train services to halt from Thursday to Sunday due to ...

Sydney's rail network will grind to a halt between Thursday and Sunday due to industrial action by the Rail Tram and Bus Union (RTBU).

The union had put an ultimatum to the NSW government to either run all rail lines around the clock from Thursday to Sunday, or face a complete shutdown.

The government agreed to that last weekend but said that would not be possible this week, instead proposing to run a 24-hour service between Hornsby and Strathfield.

Transport Minister Jo Haylen said the union rejected that offer at a meeting on Tuesday, opting to go ahead with the industrial action.

Jo Haylen says running trains 24 hours a day is not sustainable.  (ABC News: Keana Naughton)

The industrial action will impact Sydney inter-city and suburban lines only between 10pm on Thursday to 6am on Sunday.

However, a Transport for NSW spokesperson told the ABC that train services will end roughly two hours beforehand on Thursday to allow for trains to return back to base.

Ms Haylen said it was not possible for the state government to sustain 24-hour train services over the weekend.

"If we continue to try and run 24-hour services over the weekend that fact is that it will eventually lead to the failure of our rail network," Ms Haylen said.

Ms Haylen said the industrial action would cause "major disruption for millions of train passengers" across Sydney.

Passengers have been urged to avoid peak travel times on those days.

The state government has offered rail workers a 9.5 per cent pay rise over three years. (AAP: Bianca De Marchi)

Transport for NSW is preparing for alternative services, including buses for major events over the weekend and school services.

It is the latest action by the RTBU in a six-month stand-off with the state government to secure better pay and conditions.

The union is demanding a 32 per cent pay rise over four years — or 8 per cent pay rise a year — and a 35-hour working week.

However, the state government has offered rail workers a 9.5 per cent pay rise over three years.

RTBU secretary Toby Warnes accused the state government and Sydney Trains of not negotiating in good faith.

"We've seen the transport minister come out three times in the last 24 hours, which is more times the NSW government has negotiated with us," Mr Warnes said.

"All we're doing is calling on the government to come back to the negotiating table and get this deal done."

Ms Haylen has urged the RTBU to come to a resolution as soon as possible.

"My door is always open, and I would welcome the union withdrawing these bans at any time," she said.

Sydney Trains chief executive Matt Longland said the strike would cause major delays. 

Sydney Trains chief executive Matt Longland said the industrial action would cause major delays across the city's train network, which carries 1 million people per day.

"At this point we have to prepare for no train services," he said.

"I'm asking people to think about travelling well outside the peak, to make alternative arrangements, to plan well ahead."

Mr Longland said Sydney Trains had requested support from Sydney Metro for additional services on Thursday and Friday before the Metro closes this weekend for maintenance.

"That will be an additional factor as we look towards the weekend that we will not have Metro services to augment a stoppage at Sydney trains," he said.

Passengers have been urged to make alternative arrangements. (AAP: Glenn Campbell)

About 70,000 Pearl Jam fans expected to descend upon Sydney Olympic Park on Thursday and Saturday evening.

Mr Longland said attendees should make alternative travel plans.

"We will have no major event buses at this stage, we will reply on car parks, carpooling and ride share services," he said.

Jo Haylen has asked the rail union to come to a resolution.  (AAP: Flavio Brancaleone)

NSW Transport Secretary Matt Murray said alternative services would not be able to carry the same number of passengers who usually travel on Sydney Train services. 

"A million people a day are carried by the Sydney Trains network and it's simply not possible to accommodate them on alternative services no matter which mode," he said.

Mr Murray asked passengers to prepare ahead for the disruption and consider travelling well outside peak hours to get to work or appointments. 

"I'm asking people now to think about travelling well outside the peak to make alternate arrangements, to plan well-ahead with any urgent appointments across the Thursday to Sunday period and please be kind and patient to each other … and to our transport staff."