He was responding to a question from DA parliamentary leader Lindiwe Mazibuko.

She wanted to know if the president would give assurances that the ANC's investment arm, Chancellor House, and similar investment arms owned by labour federation Cosatu and the SACP, would not benefit from the R700- billion infrastructure investment programme.

Zuma said there was no law preventing politically connected individuals or companies from entering into business ventures.

"I still have to see a law that says a company of this nature and of that nature is not allowed to participate in economic activities. I'm not sure that if such companies do participate it can be called corruption.

"If you have a company established, following all the necessary procedures and rules and laws, and through its own presentation it wins the tender, is that corruption? That's a new definition of corruption," he said.

Chancellor House has come under criticism for having a stake in Hitachi, a company that supplies boilers for Eskom's Medupi power station.

Recently, Cosatu was embarrassed when it was revealed that its investment arm Kopano Ke Matla had a stake in a firm that is benefiting from the controversial e-tolling of Gauteng freeways. The labour federation has been a vocal critic of the user-pay principle of financing the investments made on Gauteng freeways.

Zuma said that when it came to participating in business, the constitution did not allow for discrimination on the basis of political affiliation.

"I don't think there are citizens in this country who, because they are members of the DA or whatever, they can't have businesses.

"I don't think there is anything that says such a thing in the constitution. If you aspire to be a businessperson, you create your company; you follow the rules . why should you be punished because you happen to think in a particular way politically? I think that is not constitutional," he said.

Zuma assured MPs that the private sector would be invited to bid for state contracts to help the government complete its infrastructure development programme.

This was after MPs inquired about mixed messages emerging from his administration about private-sector involvement in the infrastructure programme.

Public Enterprises Minister Malusi Gigaba had previously ruled out greater private-sector involvement in the upgrading of roads, ports, railways and other infrastructure.

In February, Brian Molefe, CEO of transport utility Transnet, said he did not envisage the granting of concessions that would allow the private sector to play a role in managing some of South Africa's ports.

This is despite a plea by Finance Minister Pravin Gordhan that private sector involvement in the infrastructure development programme be guaranteed.

Zuma said a conference would be arranged with key members of the private sector to plan how best to get them to help the government in its building programme.

"That question of us dealing with the private sector is uppermost because the government alone cannot deal with infrastructure. We need the investment," he said.