The rail workers dispute over pay and conditions is edging closer to resolution, with Sydney Trains boss Howard Collins scheduled to put a new offer to 200 union delegates on Thursday.

Rail Tram and Bus Union (RTBU) secretary Alex Claassens thinks delegates would agree to put the offer to members, because it was likely the best they were going to get.

On Thursday, the Fair Work Commission ordered rail unions to call off a strike scheduled for Monday and end a ban on drivers' overtime which would also have affected train operation.

FWC senior deputy president Jonathan Hamberger found the strike threatened to endanger the welfare of the community and would cause significant damage to the economy.

NSW Premier Gladys Berejiklian said it was a "huge relief" the strike would not take place on Monday.

"Now we have certainty. Business as usual," Ms Berejiklian said on Thursday.

"I'm urging everybody from today to restore good faith, maintain good faith, in all negotiations moving forward."

Offer won't be sent by text message

Union negotiations with rail operators continued until about 5:00pm on Thursday with two documents produced — one for Sydney Trains and one for NSW Trains — that "sorted out" concerns about conditions, Mr Claassens said.

A text message sent out to Rail, Tram and Bus Union NSW train workers early in the week. ( ABC News: Sarah Gerathy )

Pay talks would continue on Monday, with an offer of 2.75 per cent annually over four years already on the table.

If union delegates agreed, the new offer would be put to workers at each depot, before a formal vote is taken.

Mr Claassens was criticised over what he describes as a "straw poll" of members, taken by automated text message, which led to the previous offer being rejected, and the industrial action of a ban on overtime going ahead on Thursday.

"I'm not doing that again," he said, suggesting any future poll would be conducted formally, perhaps by the Electoral Commission.

The commission's order to end industrial action had made his members frustrated and angry Mr Claassens said.

"My members are devastated because we've lost the right to strike," he said.

"The industrial rules are broken … if we are never allowed to strike, what's the point of having and industrial relations system that has strike rules?"

Sydneysider relying on trains were warned that disruption and delays may continue over the Australia Day long weekend as it would take time for rosters adjust while the overtime ban is wound back.