CESA said it found a report by the auditor general, which outlined government's use of consultants, concerning.

The report showed that national government departments spent R33.5 billion on consultants over three years, and value for money was not achieved in all cases.

CESA CEO Graham Pirie said he was concerned the report painted all consultants with the same brush.

He agreed that no proper management controls were in place, specifically with regard to payments for services.

"This is evident in the fact that the public sector entities as reflected in the three spheres of government still owe to the tune of R1bn in delayed payments to consulting engineering firms," said Pirie.

CESA represents 480 firms employing just over 22 000 staff.

Pirie said concerted efforts were made to ensure proper controls were in place so CESA members could perform their duties based on sound ethical principles.

He said government should be spending more on engineering consultants, who could help unlock projects, and improve infrastructure spend and delivery.

"Engineers play a vital role in partnering with government as their trusted adviser to ensure sustainable solutions that provide both quality and value are procured by the various departments and at the same time providing skills transfer to mentor and train government personnel to ensure continued service delivery."