NSW Teachers Federation senior vice-president Amber Flohm told The Daily Advertiser the union had approached the education department in May to offer "10 additional hours of face-to-face learning for HSC students only".

The suggestion came amid the COVID-19 lockdown, when students were encouraged to learn from home.

"It was meant to be a targeted catch up time for students who have been extremely disadvantaged this year," Ms Flohm said.

"We made an offer to give 10 hours of face-to-face learning to senior students from the beginning of term two, but we wanted remuneration for that extra work."

The Teachers Federation's Riverina organiser, John Pratt, said "10 hours is not an unreasonable amount of time" for teachers to be regularly offering their senior classes.

"It's probably a fraction of what overtime they would be normally doing," Mr Pratt said.

"The department declined the offer and I think that shows they are happy to exploit the goodwill of our teachers."

The NSW Department of Education did not comment on why it knocked back the face-to-face sessions.

"HSC teachers commit to providing a range of supports for their HSC students as they prepare for exams both during and outside school hours this year and every year," a spokesperson said

The spokesperson said the education department had consulted with HSC teachers.

In term two, it deployed additional online resources through the 'HSC Hub'.

"The department asked HSC teachers what would best help them support their students and they suggested that an online pool of resources and additional devices would be the most beneficial," the spokesperson said.

"More devices are available for those who need them."

This year, the department also provided more than 52,400 new computers and 8440 internet dongles to families and schools.

But Ms Flohm said the resources paled in comparison to the "work of good teachers inside the classroom".

"It's become clear through the pandemic that many students who were already disadvantaged and those who live in regional communities faced greater challenges," she said.

"I think a lot of people now have a greater understanding of how relational our profession really is."

In 2018, well before the COVID-19 pandemic, the NSW Teachers Federation surveyed 18,234 public school teachers and found the majority of them were working upwards of 50 hours a week.

Mr Pratt expects the conditions to have only worsened this year as teachers "learnt a completely new system of teaching, practically overnight".

"Our HSC students are heading into their trials - some even this week - teachers are pulling out all the stops, as they always do, to help their students," he said.

In response, a spokesperson for the NSW Department of Education said: "Teachers need to discuss any workload issues with their principal or [turn to] colleagues for advice and support."