Workers at the National Energy Regulator of SA (Nersa) will go on strike on Wednesday, their union said on Tuesday.

The National Health, Education and Allied Workers' Union (Nehawu) said it had declared a dispute following a deadlock in salary negotiations and it would be embarking on strike action from Wednesday.

"The union reaffirms its determination in ensuring that the current global economic crisis is not used as an excuse to reverse the gains workers have scored over the years and has therefore decided to lead its members to the streets," said spokesman Sizwe Pamla in a statement.

Nehawu's chief negotiator Tshepiso Mogorosi said the union was demanding a 15 percent salary increase and wanted workers to be paid market-related salaries.

He said the employer had unilaterally implemented a 7.5 percent wage increase.

Nersa was not immediately available for comment.