Minimal supervision will be in place across public schools in the Southern Highlands today after the Teachers Federation decided to take 24 hour industrial action.
The union has raised serious concerns about teacher shortages.
Members are also calling for better pay and working conditions.
Teachers Federation Organiser for the Southern Highlands Duncan McDonald said the situation in the Wingcarribee and Shoalhaven is dire.
"The Government figures that were released to State Parliament last October showed that 43 per cent of schools in the Shoalhaven and Southern Highlands had vacant permanent teaching positions,
"Now that shortage has actually grown this year according to figures provided in February,"Mr. McDonald said.
Image: NSW Teachers Federation via Facebook