A $264 million olive branch has been extended to railway workers to ease train safety concerns and prevent more disruption, but their union says it has been “burned too many times” to get the oral deal.

The Rail, Tram and Bus Union is engaged in long-running negotiations with the government over security adjustments it wants for the $2.8 billion intercity fleet made in Korea.

Train drivers have been campaigning for months to pressure the government, which finally relented on Wednesday and agreed to spend $264 million to upgrade the shut down fleet.

Transport Secretary David Elliott said a verbal agreement had been reached and he expected the union to end this week’s union action.

“We have agreed to their (union) request for one agreement and all original discussions and negotiations regarding their compensation and salary have also been agreed,” he told reporters on Wednesday.

“The NSW government expects the union to immediately end the union action in the interests of commuters.”

He said the settlement has been reached so that the train system can run smoothly again without interruptions, noting that “it’s a small price to pay”.

“The cost of modifying these perfectly good trains is much less than actually disrupting our economy and not letting these trains run,” said Mr. Elliott.

However, the RTBU said on Wednesday that it needs the guarantees in writing and continues with its union action.

Rail workers and commuters have been burned too often to believe what a minister says in one meeting, said union secretary Alex Claassens.

“We need to see the whole package in writing to make sure this isn’t just another case of the NSW government playing political games.”

Transport for NSW warned that the union’s ban on running foreign trains on Friday would have a knock-on effect on Sydney’s services, with a 70 per cent reduction during peak periods leading to delays and cancellations.

Dominic Perrottet’s government has also fought against union actions by the teachers’ union.

A historic 24 strike on Thursday by NSW public and Catholic teachers is the result of the state government’s failure to address chronic teacher shortages, unions say.

The action by 85,000 teachers in public and Catholic schools will be the third strike in six months and is expected to affect about a million families just one day before two weeks of vacation.

Thousands of teachers are expected to descend on Sydney’s CBD after the NSW budget offered no more than a 3.5 percent pay rise.

It is the first time in more than 25 years that the NSW Teachers Federation and Independent Education Union NSW/ACT have joined forces for a 24-hour strike.

“We have a crisis in the form of a teacher shortage, a crisis that the government has created itself,” federation president Angelo Gavrielatos told reporters on Wednesday.

“The government has known for years the causes of this crisis: uncompetitive salaries and unsustainable work pressure.

“Students have been denied not only their learning opportunities, but also their future.”

Mr Gavrielatos urged the government to keep teachers in the stretched sector by raising wages by about seven percent to keep up with inflation and the cost of living that has risen in recent months.

“Teacher salaries have fallen over the past 30 years relative to other professions…our claim is clear based on an independent study…which recommends an increase of five to 7.5 percent per year,” he said. .