The R1,2-million spent by Eskom on a ceremony to mark the reopening of its Camden power station in Mpumalanga earlier this year, was not all spent on the lunch, the utility said on Tuesday.

"It wasn't just lunch, it was the whole event," spokesperson Hilary Joffe told Sapa, responding to questions about the event.

Camden is one of three power stations that Eskom is returning to service to meet South Africa's demand for electricity. It was mothballed in 1988.

The amount spent at the plant's October 23 reopening, attended by President Jacob Zuma, was revealed in a written reply by Public Enterprise Minister Malusi Gigaba to a parliamentary question, posed by the Democratic Alliance.

"The nature of the event... [was] a luncheon, which included presentations and [a] plant tour of Camden," he said in the reply, adding it had cost R1,2-million and involved 300 guests.

In a statement earlier on Tuesday, the DA said it would be raising questions at Parliament about the reopening event, which it labelled an "obscene splash" and a "frivolous and self-indulgent" waste of public resources.

"The DA is stunned that Eskom spent R1,2-million on a single lunch party for delegates at the reopening of the coal-fired Camden power station in Mpumalanga during October of this year," DA MP Lindiwe Mazibuko said.

Joffe said the actual cost of catering at the event was "less than R300 000".

Lunch had been served to 300 invited guests plus 350 power station employees, as well as various "security people, crew and other workers".

She said the balance of the R1,2-million (R900 000) had been spent on "marquees, air conditioning and audio-visual and sound systems, as well as the logistics that go into this type of event".

Eskom was mindful of the need to curb expenses, but did "not feel we spent an excessive amount" on the reopening, Joffe said.

Mazibuko said the DA would be calling on Eskom chief Brian Dames to explain the spending to Parliament's public enterprises portfolio committee.

"This wasteful expenditure is doubly worrying because Eskom continually requires publicly financed bailouts for its operations.

"Between 2005 and 2009, Eskom was the recipient of R188,67-billion in state financial assistance, and this year new bailouts have been announced – including guarantees totalling R176-billion that were confirmed in March by former minister Barbara Hogan, and another R20-billion that the presidency recently claimed would be allocated in next year's budget.

"The DA would like to know whether any of Eskom's R20-billion bailout money is intended for its catering department? If so, does the ANC government really think this is how it should be spending precious state resources?" she said.