South Africa's nine provinces are a bulwark of democracy and should not be scrapped, Democratic Alliance (DA) leader Helen Zille said on Monday.

Zille, in a speech at the Wits Graduate School of Public and Development Management, said the diffusion of power between different centres was a concept that lay at the heart of South Africa's Constitution.

"If you read the Constitution, it is clear that the provinces should be the bulwark of our democracy," she said.

"Provinces are now under threat. And, if this threat materialises, our democracy is at risk."

In June, Cooperative Governance Minister Sicelo Shiceka said the government would decide on the future of the provinces by March next year.

Zille said all indications are that the African National Congress (ANC) had made up its mind about the future of the provinces, and that it was now merely "going through the motions to provide a façade of analysis and consultation".

"This undermines the very essence of due process envisaged in the Constitution," she said.

The ANC had used an argument that provinces are a relic of apartheid as an ANC excuse to centralise power.

Zille said she had raised this issue directly with President Jacob Zuma.

"I have assured him of the provincial government's complete commitment and loyalty to the Constitution and its objectives."

She said the scrapping of, or merging of provinces, would turn them into mere administrative units of central government.

South Africa' Constitutional negotiators understood that the diffusion of power was one of the essential aspects to providing the necessary checks and balances to prevent too much power being concentrated in too few hands.

She said the drawing up of provincial boundaries was a deeply democratic outcome.

"It is probably true to say that South Africa would not have had a negotiated settlement unless there was agreement on the provinces."

A belief among the public that removing the provincial sphere, would streamline government, reduce costs and improve efficiency is unfounded, she said.

"There are ministries, departments, projects and parastatals under central government control that are more corrupt and inefficient than almost anything governed under concurrent provincial powers.

"As for the argument that costs would be saved by scrapping or merging provinces, this would be insubstantial, if indeed there would be any at all.

"The services provided by the provinces would have to be continued through decentralised arms of the central State, so there would be no savings in administration and infrastructure.