Parliament will act decisively against heads of government departments who do not sign performance agreements, the Portfolio Committee on Public Service and Administration said on Thursday.

A delegation from the Public Service Commission (PSC) told the committee this week that a large number of department heads were not signing performance agreements and could therefore not be evaluated.

"This is a very serious matter and as Parliament we will leave no stone unturned to get this area right," committee chairperson Joyce Moloi-Moropa said.

According to the PSC, heads of government departments were being issued with merit awards by the different departments.

Even though the performance agreements were a useful management tool, they were in some cases only used for compliance purposes and often contained poor content.

Supervisors were using them for punitive rather than developmental purposes, the committee heard.

Another issue that arose in the briefing was of the involvement of civil servants in private businesses.

"We need to evaluate if their involvement in extra business activities do not impact negatively on their performance," the committee said in a statement.

"Are we receiving value for money in terms of the salaries government pay them and the output thereof?" it asked.

The PSC had to check whether these civil servants had obtained permission from their seniors to receive extra income as per government regulation.