The DA wants the National Energy Regulator of SA to probe the way Eskom's tariff hike, approved earlier this year, was applied by municipalities.

The party would ask the regulator to look into the electricity price hikes by 60 municipalities, spokesman on co-operative governance and traditional affairs, Willem Doman said in a statement on Wednesday.

Forty of these did not apply for higher tariffs and 20 handed in late applications.

"Specifically the 40 municipalities which did not apply for permission might have implemented extreme tariff hikes, which now puts an extreme financial burden on the public."

Doman was referring to Eskom's 31.1 percent price hike approved by Nersa in June.

He said when the price at which Eskom delivered power to municipalities increased significantly, municipalities could add a lower percentage increase and still stay financially sound. If they stuck to the same percentage consumers would be hit harder.

"Municipalities should do all they can to buffer Eskom's sharp increases."

He called for the probe to extend to all municipalities and added that Nersa should have followed up on the 60 municipalities "more forcefully".

"At the moment these municipalities apply tariffs which are technically unlawful. At the same time these tariffs were approved at municipal council meetings, were made public and might be reasonable in some cases," he said.

"[T]he non-compliance of these 60 municipalities is further evidence of the rot that has set in at our municipalities and that the expertise to implement administrative procedure correctly do not exist."

Nersa could not immediately be reached for comment.