THE construction of power utility Eskom’s long-awaited Medupi power station in Lephalale in the Limpopo province hit another obstacle on Wednesday when construction workers downed tools.

Eskom spokeswoman Hilary Joffe said the station was temporarily closed.

"Construction workers held protest action this morning and Eskom sent the workers home for safety reasons," she said.

No injuries or damage were reported. Eskom was working with contractors to restore the operations, she said.

The closure could put more pressure on the schedule for the power station’s completion.

The schedule is already under the spotlight because of repeated delays.

In 2011, Eskom said Medupi’s schedule had been affected by performance on the boiler contracts. Thousands of protesters torched two buses in 2011 and damaged four vehicles during a strike at the Medupi site, with the police saying residents claimed Eskom had employed experienced foreign boiler makers without considering the locals for the positions.

In September last year, about 80 workers contracted by Murray & Roberts Construction and Grinaker-LTA damaged several vehicles and some equipment at the power plant. The workers protested because the contracts of about 600 local employees were due to end.

National Union of Metalworkers of South Africa general secretary Irvin Jim said workers were striking over various issues, including a lack of training and inadequate working conditions and food.

"They do not give workers basic benefits. They give us rotten food and labour brokers abuse us," he said.

The 4,764MW power station should have been commissioned last year, but the deadline was pushed back to this year.

Commissioning the plant will be a major milestone for South Africa, as the additional capacity would provide extra power for South Africa’s constrained national grid supply.

With Alistair Anderson and Siseko Njobeni