A mass strike by members of South Africa's engineering profession threatens to take a heavy toll on the health of the country's economy.

Members of the National Union of Metalworkers of South Africa (NUMSA) have launched a nation-wide strike following the breakdown of last-minute wage discussions with employers.

NUMSA is South Africa’s biggest union, with more than 220,000 members servicing the construction and engineering sectors of sub-Saharan Africa’s biggest economy.

The union announced that it would stage marches in several of the country’s major cities, including Johannesburg, Cape Town and Durban.

NUMSA is demanding that companies raise wages by 12 per cent across the board – more than twice the current rate of inflation, and insisting those companies provide increased housing allowances and rescind the use of labour brokers.

The launch of the strike arrives in the wake of a five-month long strike in the platinum sector, which many consider the chief reason for a 0.6 per cent contraction in national economy during the first quarter of 2014.

The current strike could have an even bigger impact on the South African economy as it will affect a broader swathe of its productive industries. The actions of the union are expected to severely hinder the prospects of construction, engineering, automobile and manufacturing firms, potentially dragging the country into recession should its economy suffer a second consecutive contraction during the June quarter.

Analysts believe the strike will reduce growth in South Africa this year to less than two per cent and will cost the the national economy over US$28 million per day.

The strike could also hamper the economy by further impeding the provision of electricity, the intermittence of which has been blamed by many for South Africa’s ailing growth.

Union members have decided to picket the headquarters of Eskom, which is responsible for supplying South Africa with the bulk of its electricity, despite a government prohibition on strikes by employees due to the essential nature of the services that the utility provides.

Downtooling by the union will also affect the construction of two of Eko’s new power stations, which are already lagging behind schedule.