The SA Democratic Teachers' Union (Sadtu) will embark on strike action if the government does not improve its wage offer within the next seven days, officials say.

“There's still an opportunity to avert the strike... I think we are challenging the government,” Sadtu president Thobile Ntola told reporters in Johannesburg.

He said the national executive committee of Sadtu decided at a meeting on Tuesday that its 245,000 members would embark on a strike within seven days – unless a new offer acceptable to teachers was made.

The state was offering a 6.5 percent increase and a housing subsidy of R620 per month.

The union was demanding an 8.6 percent increase and a R1000 housing subsidy.

“The union will be serving a notice to the employer today wherein the employer has seven days to better the offer in order to avert the strike,” said general secretary Mugwena Maluleke.