"The DA is concerned about the capacity of state-owned enterprises to raise funds for, and implement, the building programme," said MP David Ross.

"The lack of clarity around the planned projects makes it difficult for the private sector to get involved," he said.

"With government debt approaching 40%, there is little fiscal space for the Treasury to finance the programme in its entirety, hence the reliance on state-owned enterprises."

In his medium-term budget policy statement on Thursday, Finance Minister Pravin Gordhan spoke about the Presidential Infrastructure Co-ordinating Commission's plan for implementing 18 infrastructure projects, costing R845-billion, in three years.

The projects were part of a broader initiative by the government which would result in its spending R4-trillion on infrastructure in the next 15 years.

"There are three avenues to fund [these] infrastructure projects - public funding, private-public partnerships and raising funds by taxing citizens," said Ross.

He said little detail on finance and implementation were provided by the government.

"A look at the balance sheets of Eskom and Transnet exacerbates our concerns and calls into question their capacity to raise finance without further state guarantees."

Ross said he would ask Gordhan to provide details of the proposed infrastructure programme.

"There can be no doubt that increasing investment in economic infrastructure is the right plan. [But] we need to conduct an honest review of the capabilities to finance and implement this programme," he said.