The Public Servants' Association issued its intention to strike last week after a deadlock in wage discussions.

Now Nehawu members say they too will strike after SARS made a final offer of a zero-percent increase.

Both unions are demanding increases of up to 13 percent, citing rising food and fuel prices. Nehawu -- which represents 45 percent of the workers -- is threatening to bring SARS operations to a standstill.

The revenue service chose not to respond to the latest strike announcement. A SARS official told eNCA that it will respond after another round of talks with Nehawu on Wednesday.

eNCA