Cosatu in KwaZulu-Natal on Wednesday reacted with shock at the ANC provincial leadership's decision to nullify the party's eThekwini regional conference.

"We think it is unprecedented," the Congress of SA Trade Unions said in a statement.

"Cosatu in KwaZulu-Natal respects the wisdom of the provincial executive committee of the ANC and its constitutional powers to make decisions, but is very much shocked about the pronouncements of the PEC on the nullification of Ethekwini regional conference."

On Tuesday, the provincial leadership announced the decision to reconvene the sixth regional conference.

When it was held in Durban on February 14, current eThekwini metro mayor James Nxumalo was elected chairman of the region in a tightly contested ballot that saw him edge out Zandile Gumede by 253 votes to 212.

However, after the conference was held it emerged that three branches which had not been properly audited had been allowed to participate in electing the party's office bearers for the region.

In addition, there were claims that ANC members were paid nearly R1 million to vote for Nxumalo.

This was according to a letter sent by a Durban branch deputy chairman to ANC secretary general Gwede Mantashe and KwaZulu-Natal secretary Sihle Zikalala.

The conference was cancelled three times before it was ultimately held in on February 14.

Cosatu said ignoring misconduct issues and simply reconvening a conference would not help.

There should have been an investigation, instead of "an emotional and haphazard thumb-sucked decision".

"The regional executive committee elected in the conference was not even consulted which is a painful thing, meaning that the very same REC was condemned and declared invalid the first day it assumed the office," Cosatu said.

A date for the conference still had to be determined.