Union members at the Orange school voted in favour of considering further action unless urgent action was taken in March and while the number of vacancies has reduced this year, that stance is not believed to have changed.

The Department of Education reported 16 unfilled vacancies at the school at the beginning of the year but on Tuesday said that has reduced to nine, a decline from government figures which showed a total of 13 vacancies in May.

The seven vacancies which have been filled this year include three head teacher roles and a deputy principal while it's been confirmed acting principal Chantelle Phair has agreed to stay in the relieving role until the end of 2021 as well.

"Some of the vacancies at Canobolas have been filled, which is a positive. But as it stands, I believe federation members are still considering [further action]," Teachers Federation country organiser Kelly Anderson said.

"We are still seeing shortages across the state though and schools like Canobolas, Lithgow (High School) and Walgett (Community College High) were highlighted as having significant unfilled vacancies and casual teacher shortages.

"There's no quick fix but to address the shortages things need to change to attract more teachers, the Gallop Inquiry highlighted increasing salaries compared to other professions and increasing resources to suitable levels required for teaching and learning demands."

Teachers at Lithgow, Mudgee and Forbes high schools have all walked off the job this year due to frustrations surrounding shortages, the union has reported almost 50 instances of similar action being taken around the state this year.

The Department of Education also refuted claims, received by the Central Western Daily this week, HSC students at Canobolas have been left without a mathematics and biology teacher at times this year.

"Every class at Canobolas Rural Technology High School has a qualified teacher delivering it. No HSC students have been without a teacher," a NSW Education spokesperson said.

The impact of the remaining nine unfilled vacancies at the Orange school is still a cause for concern, Ms Anderson said, although the Department of Education said they are being "actively recruited for".

Ms Anderson also explained that, state-wide, the union has noted instances of classes being split and teachers being forced to cover classes outside their subject area to ensure they are supervised.

The union highlighted the latter as an issue at Canobolas in March.

The Department of Education went on to say the vacancies at Canobolas "are not representative" of the state-wide level of about 1.5 per cent of the total workforce.

"Schools go through periods of staffing changes which is what Canobolas Rural Technology High School is experiencing. It does take longer to recruit staff in schools in regional areas, however, which is why NSW has the most comprehensive rural and remote incentives scheme in Australia," the NSW Education spokesperson said.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: