The Democratic Alliance called for Eskom chief executive officer Thulani Gcabashe to be fired as more power cuts hit the Western Cape on Tuesday.
"We call on (Public Enterprises) Minister Alec Erwin to remove Mr Gcabashe from his position," DA Cape Town mayoral candidate Helen Zille said in a media statement.
"We also call on the voters of Cape Town to fire the mayor tomorrow (Wednesday) at the polls for her own part in this mess."
Eskom more than doubled the pay packages of Gcabashe and his top managers in July last year, Zille said. Gcabashe's pay package for the 15 months ended in March 2005 amounted to R13 million.
"It is time that the bonuses stopped and someone took responsibility for this mess.
"Not only have Eskom and the (Cape Town) city failed to play open cards with the public they are supposed to serve, but the cost of this debacle to our economy will run into billions. This is an inexcusable failure."
Consumers have been told to expect "load shedding" blackouts for the rest of the week, but should anticipate "many more months of this problem", Zille said.
The most recent blackout came despite promises to stabilise the electricity supply by Monday, she added.
"The bigger picture is that between Eskom and the ANC (African National Congress-led) council, Cape Town has not been provided with sufficient electricity generation and distribution capacity to meet its level of growth.
"As a result, every time anything goes wrong, there is not enough reserve capacity to keep the lights on."
Erwin earlier said damage to the Koeberg nuclear plant had been the result of an act of sabotage.
"The investigation is ongoing and we will bring criminal charges against individuals soon," the minister said in Pretoria.
One of the two generators at Koeberg was damaged in December, causing outages in the Western Cape over the past month.
Early on Tuesday morning, the other generator at the plant was shut down automatically due to a trip in the high voltage power line.
Eskom board chairman Valli Moosa said it would take "some time" to get Koeberg up again.
Erwin said suburbs of Cape Town would go without power for periods of two hours until the generator was running again.
Eskom spokesperson Fani Zulu said a mobile team had been dispatched to investigate the cause of the fault that resulted in the tripping of the Droerivier-Bacchus transmission line at 2am on Tuesday.
"The team has reported back that sections of the voltage transmission in the Worcester area were on the ground. The equipment that holds the line to the tower is damaged," said Zulu.
"They are working on the repairing the damage, but heavy rain in the area is hampering turn-around time."
Zulu said he could not conclusively explain what caused the damage, because it could have been anything from thermal overload to foul play.
Metrorail, meanwhile, appealed to commuters in the Western Cape to find alternative transport as the early morning power outages disrupted train services.
"The train service is very erratic this morning. Commuters should make their own transport arrangements, at least for the morning peak," Metrorail spokesperson Riana Scott said.
"If anyone is stuck on a train somewhere, do not disembark until you are given instructions to do so. Commuters should not worry about getting to work late as we will inform major employers of the problem."
Scott said the Chamber of Business would be advised and would in turn inform its members that some employees would be late for work.
"Everyone knows of the outages. It's an Eskom problem, we cannot do anything."
Motorists were warned to exercise caution on the roads as traffic lights in the City Bowl area, Rondebosch, Newlands, Parow, Goodwood, and Elsiesrivier were not working.
The African Christian Democratic Party said it hoped the power cuts would not hamper the collation of Wednesday's election results.
"The ACDP calls upon the Independent Electoral Commission, its staff and independent auditors, as well as all ACDP party agents, to be particularly vigilant when votes are cast, counted and more particularly captured," it said in a statement.
"This, especially in areas experiencing power cuts or any other challenges necessitating the manual capturing and transfer of results."
The IEC said on Monday the power cuts should not affect voting, taking place in daylight hours from 7am to 7pm.
It could affect the count, but candles and lamps were on standby, said provincial electoral officer Courtney Sampson.
The so-called "zip-zip" machine, which reads the barcode in voters' identity documents and holds a copy of the voters' roll, also worked on battery power, and was not indispensable. The vote could be conducted manually if need be.
The real test, if the power went out, would come with feeding the vote counts into the IEC mainframe, Sampson said.
Electricity generators were available in all the big centres. "And anyway, we have seven days in which to declare an election. We are not too concerned," said Sampson.- Sapa